RepoFlow Error Knowledge Base

Practical troubleshooting guides for npm, pip, Maven, NuGet, .NET, and Docker errors.

Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?

The Docker CLI cannot reach the Docker daemon, usually because the engine is stopped, the context is wrong, or the socket is unavailable.

Code: connect_no_route_to_host

connect: no route to host

Docker cannot reach the registry host because the network path has no usable route, the gateway is blocked, or the destination subnet is unreachable.

Code: daemon_sock_permission_denied

Got permission denied while trying to connect to the Docker daemon socket at unix:///var/run/docker.sock

Docker cannot access /var/run/docker.sock because your user lacks permission to the daemon socket or the socket ownership is wrong.

Code: denied_requested_access

docker: denied_requested_access

Docker denied access because the repository path is wrong, the image is private, or the provided credentials do not have permission.

Code: dial_tcp_connection_refused

dial tcp: connection refused

Docker got a connection refused while trying to reach either the registry endpoint or the DNS resolver used to look it up.

Code: exec_not_found

exec: "python": executable file not found in $PATH

Docker started the container, but the configured command or entrypoint was not found in the image PATH or at the specified path.

Code: exec_permission_denied

Error response from daemon: oci runtime error: exec: "/path/to/executable": permission denied

The container entrypoint exists, but Docker cannot execute it because the file lacks execute permissions or the mount blocks execution.

Code: id_not_found

Error response from daemon: id not found

Docker could not find the referenced container, image, network, or volume ID, usually because it was deleted, mistyped, or belongs to another context.

Code: invalid_reference_format

docker: invalid reference format: repository name must be lowercase

Docker rejected the image name because the reference format is invalid, commonly due to uppercase letters, bad tagging, or malformed syntax.

Code: invalid_reference_lowercase

invalid reference format: repository name must be lowercase

Docker rejected the image reference because repository names must be lowercase, so uppercase letters or malformed syntax made it invalid.

Code: io_timeout

Error response from daemon: i/o timeout

Docker hit an i/o timeout while contacting the registry, usually because of DNS, proxy, firewall, or slow network connectivity.

Code: manifest_unknown

Error response from daemon: manifest for <image>:<tag> not found: manifest unknown: manifest unknown

Docker could not find the requested manifest for that image tag, which usually means the tag does not exist or the registry metadata is out of date.

Code: no_matching_manifest

no matching manifest for linux/amd64 in the manifest list entries

Docker found the image tag, but no manifest matches your OS or CPU architecture, so the image is not built for your platform.

Code: no_such_image

Error: No such image: <image-id>

Docker cannot find that image locally, so the image ID or tag is wrong, was removed, or was never pulled onto this machine.

Code: push_tag_not_exist

Error pushing to registry: Tag does not exist: <tag>

Docker cannot push the image because the tag does not exist locally, so you need to tag the image correctly before pushing.

Code: registry_503_service_unavailable

Error response from daemon: Get https://registry-1.docker.io/v2/: Service Unavailable

Docker reached the registry over HTTP, but the registry or reverse proxy returned HTTP 503 because the service was unhealthy or overloaded.

Code: repository_not_exist

FATA[0000] Repository does not exist: <user>/<repo>

Docker cannot pull from that repository because the name is wrong, the repository does not exist, or your account lacks access.

Code: timeout_exceeded

request canceled while waiting for connection (Client.Timeout exceeded while awaiting headers)

Docker timed out while waiting for the registry response, which usually points to slow network links, proxy issues, or an overloaded registry.

Code: too_many_requests

Docker rate limit exceeded error

Docker Hub rejected the pull because you hit its rate limit, often fixed by authenticating, waiting, or using a cached mirror.

Code: unable_to_remove_filesystem

Error: Unable to remove filesystem for <container-id>: Device or resource busy

Docker cannot remove the container filesystem because the device is busy, usually due to running processes, mounts, or lingering references.

Code: unauthorized_authentication_required

unauthorized: authentication required

Docker registry authentication failed because no valid credentials were sent, so you need to log in or fix the token used for that registry.

Code: unauthorized_incorrect_password

unauthorized: incorrect username or password

Docker login failed because the registry rejected the username or password, so the stored credentials or access token are wrong.

Code: volume_in_use

Error response from daemon: Conflict: volume is in use

Docker cannot remove the volume because a running or stopped container still references it, so you must detach or delete the dependent container first.

Code: CERT_HAS_EXPIRED

npm ERR! code CERT_HAS_EXPIRED

npm rejected the HTTPS connection because the registry or proxy certificate is expired, so the TLS handshake can no longer be trusted.

Code: CERT_REVOKED

npm ERR! code CERT_REVOKED

npm rejected the HTTPS certificate because the registry or proxy certificate has been revoked and is no longer trusted.

Code: CERT_SIGNATURE_FAILURE

npm ERR! code CERT_SIGNATURE_FAILURE

npm rejected the registry TLS certificate because the certificate chain signature could not be verified by your local trust store.

Code: CERT_UNTRUSTED

npm ERR! code CERT_UNTRUSTED

npm does not trust the registry certificate chain, usually because of a missing internal CA, corporate proxy, or intercepted HTTPS traffic.

Code: DEPTH_ZERO_SELF_SIGNED_CERT

npm ERR! code DEPTH_ZERO_SELF_SIGNED_CERT

npm received a self-signed certificate at the top of the TLS chain, usually from a private registry or HTTPS-inspecting proxy.

Code: E401

npm ERR! code E401

npm received a 401 Unauthorized response from the registry because your token, password, or .npmrc authentication settings are missing or invalid.

Code: E403

npm ERR! code E403

npm was authenticated, but the registry returned 403 Forbidden because your account lacks permission for that package, scope, or action.

Code: E404

npm ERR! code E404

npm returned 404 because the package, version, scope, or registry URL does not exist at the registry you are using.

Code: E409

npm ERR! code E409

npm received HTTP 409 Conflict because that package version already exists or the registry state conflicts with the publish request.

Code: E422

npm ERR! code E422

npm received HTTP 422 because the publish payload was semantically invalid, such as bad metadata, malformed tarball data, or invalid package state.

Code: EACCES

npm ERR! code EACCES

npm hit EACCES because the current user does not have permission to read, write, or execute one of the required files or directories.

Code: EAI_AGAIN

npm ERR! code EAI_AGAIN

npm could not resolve the registry hostname because DNS returned EAI_AGAIN, a temporary lookup failure that usually clears on retry.

Code: EBADENGINE

npm ERR! code EBADENGINE

npm returned EBADENGINE because the package declares Node.js or npm engine requirements that do not match the versions running your install.

Code: EBADPLATFORM

npm ERR! code EBADPLATFORM

npm returned EBADPLATFORM because the package does not support the current operating system, CPU architecture, or runtime combination.

Code: EBUSY

npm ERR! code EBUSY

npm hit EBUSY because a file or directory was locked or still in use by another process, editor, antivirus tool, or sync service.

Code: ECONNABORTED

npm ERR! code ECONNABORTED

npm aborted the network request before completion, often because the remote server closed the connection or a proxy interrupted it.

Code: ECONNREFUSED

npm ERR! code ECONNREFUSED

npm reached the registry host, but the TCP connection was refused, usually because the server, proxy, or mirror is not accepting connections.

Code: ECONNRESET

npm ERR! code ECONNRESET

npm lost the network connection because the peer reset the TCP session mid-request, often due to proxies, firewalls, or flaky networks.

Code: EEXIST

npm ERR! code EEXIST

npm hit EEXIST because it tried to create a file or directory that already exists where npm expected to create a new one.

Code: EINTEGRITY

npm ERR! code EINTEGRITY

npm downloaded a package tarball whose checksum did not match the expected integrity value (lockfile/metadata mismatch).

Code: EINVALIDPACKAGENAME

npm ERR! code EINVALIDPACKAGENAME

npm rejected the package name because it does not follow npm naming rules, such as invalid characters, uppercase letters, or reserved names.

Code: EINVALIDTAGNAME

npm ERR! code EINVALIDTAGNAME

npm rejected the dist-tag because the tag name is invalid, reserved, or formatted in a way that conflicts with version parsing.

Code: EINVALIDVERSION

npm ERR! code EINVALIDVERSION

npm rejected the version because the semver string is invalid or malformed in package metadata, tags, or your command.

Code: EISDIR

npm ERR! code EISDIR

npm hit EISDIR because it expected a file path, but the target resolved to a directory instead, so npm could not read or write it correctly.

Code: EJSONPARSE

npm ERR! code EJSONPARSE

npm could not parse package.json because the JSON is invalid, such as trailing commas, mismatched quotes, or broken syntax.

Code: ELIFECYCLE

npm ERR! code ELIFECYCLE

npm returned ELIFECYCLE because a package lifecycle script like install, test, or build exited with a non-zero status.

Code: ELOCKVERIFY

npm ERR! code ELOCKVERIFY

npm returned ELOCKVERIFY because the lockfile and installed dependency tree do not agree with what npm expected to verify.

Code: ELSPROBLEMS

npm ERR! code ELSPROBLEMS

npm ls reported ELSPROBLEMS because the installed dependency tree contains missing, invalid, or extraneous packages.

Code: EMFILE

npm ERR! code EMFILE

npm hit EMFILE because the process opened too many files at once and exceeded the per-process file descriptor limit.

Code: ENAMETOOLONG

npm ERR! code ENAMETOOLONG

npm hit ENAMETOOLONG because the generated file path exceeded your operating system path length limit during install or extract.

Code: ENEEDAUTH

npm ERR! code ENEEDAUTH

npm requires authentication for this registry or package, so you must log in or configure a valid auth token in .npmrc.

Code: ENFILE

npm ERR! code ENFILE

npm hit ENFILE because the whole system reached its open-file limit, so new files or sockets could not be opened.

Code: ENOENT

npm ERR! code ENOENT

npm hit ENOENT because a required file or directory was missing, often package.json, a lockfile path, or an extracted dependency.

Code: ENOSELF

npm ERR! code ENOSELF

npm returned ENOSELF because the package name matches the project you are trying to install, creating a self-dependency.

Code: ENOSPC

npm ERR! code ENOSPC

npm hit ENOSPC because the disk ran out of free space while extracting packages, writing cache data, or updating node_modules.

Code: ENOTDIR

npm ERR! code ENOTDIR

npm hit ENOTDIR because it expected a directory in the path, but a file exists there instead, breaking the package or cache lookup.

Code: ENOTEMPTY

npm ERR! code ENOTEMPTY

npm hit ENOTEMPTY because it tried to replace or remove a directory that still contains files, often during install, cleanup, or rename steps.

Code: ENOTFOUND

npm ERR! code ENOTFOUND

npm could not resolve the registry hostname, so DNS lookup failed before npm could connect to the package registry.

Code: EOTP

npm ERR! code EOTP

npm requires a one-time password for this publish or settings change because two-factor authentication is enabled on the account.

Code: EPERM

npm ERR! code EPERM

npm hit EPERM because the operating system denied the filesystem operation, commonly due to permissions, locks, antivirus, or Windows file handling.

Code: EPIPE

npm ERR! code EPIPE

npm hit EPIPE because it tried to write output to a closed pipe or terminated process, often in CI logs or shell pipelines.

Code: EPUBLISHCONFLICT

npm ERR! code EPUBLISHCONFLICT

npm could not publish because that package version already exists in the registry, so you need a new version before publishing again.

Code: ERESOLVE

npm ERR! code ERESOLVE

npm failed with ERESOLVE because it could not build a dependency tree that satisfies the requested versions and peer dependency constraints.

Code: EROFS

npm ERR! code EROFS

npm hit EROFS because it tried to write cache or package files on a read-only filesystem, mount, or container layer.

Code: ERR_SOCKET_TIMEOUT

npm ERR! code ERR_SOCKET_TIMEOUT

npm hit a socket timeout while waiting for registry network I/O, usually because of slow connections, proxies, or an overloaded registry.

Code: ETARGET

npm ERR! code ETARGET

npm returned ETARGET because no published version matches the version range or dist-tag requested in your install command.

Code: ETIMEDOUT

npm ERR! code ETIMEDOUT

npm timed out while talking to the registry or downloading a package tarball, usually because of slow networks, proxies, or registry issues.

Code: EUSAGE

npm ERR! code EUSAGE

npm returned EUSAGE because the command, flags, or configuration were invalid for that operation, so npm stopped before doing any work.

Code: HOSTNAME_MISMATCH

npm ERR! code HOSTNAME_MISMATCH

npm connected over HTTPS, but the certificate presented by the server does not match the registry hostname you requested.

Code: SELF_SIGNED_CERT_IN_CHAIN

npm ERR! code SELF_SIGNED_CERT_IN_CHAIN

npm rejected the TLS connection because a self-signed certificate appeared somewhere in the certificate chain to the registry.

Code: UNABLE_TO_GET_ISSUER_CERT

npm ERR! code UNABLE_TO_GET_ISSUER_CERT

npm could not build a trusted TLS chain because the issuer certificate for the registry was missing or unavailable.

Code: UNABLE_TO_GET_ISSUER_CERT_LOCALLY

npm ERR! code UNABLE_TO_GET_ISSUER_CERT_LOCALLY

npm could not verify the registry TLS chain because the issuer certificate is missing from the local machine trust store.

Code: UNABLE_TO_VERIFY_LEAF_SIGNATURE

npm ERR! code UNABLE_TO_VERIFY_LEAF_SIGNATURE

npm could not verify the registry TLS certificate because the leaf certificate chain is incomplete or the required issuer is missing locally.

Code: DEPENDENCY_RESOLUTION_FAILURE

Could not resolve dependencies for project

Maven could not resolve one or more project dependencies, usually because of missing artifacts, bad repository settings, or network access problems.

Code: FAILED_TO_READ_ARTIFACT_DESCRIPTOR

Failed to read artifact descriptor for <artifact>

Maven could not download or parse the POM for a dependency/plugin, so it cannot resolve that artifact's transitive dependencies.

Code: FAILURE_TO_FIND_ARTIFACT

Failure to find artifact

Maven could not find an artifact in the configured repositories, and the missing result may be cached in the local repository.

Code: NON_RESOLVABLE_PARENT_POM

Non-resolvable parent POM

Maven cannot resolve the `<parent>` POM for your project from the local filesystem or configured repositories.

Code: NO_POM_IN_DIRECTORY

The goal you specified requires a project to execute but there is no POM in this directory

You ran a Maven goal that needs a `pom.xml`, but Maven cannot find one in the current directory (or via `-f`).

Code: COULD_NOT_TRANSFER_ARTIFACT

Could not transfer artifact ...: transfer failed

Maven could not transfer the artifact from the repository, usually because of network failures, proxy issues, TLS problems, or bad credentials.

Code: PKIX_PATH_BUILDING_FAILED

PKIX path building failed

The JVM running Maven cannot validate the HTTPS certificate chain of the repository, so Maven refuses the connection.

Code: REPOSITORY_UNAUTHORIZED_401

Return code is: 401, ReasonPhrase: Unauthorized

The repository requires authentication, but Maven did not send valid credentials for the repository `<id>` being used.

Code: REPOSITORY_FORBIDDEN_403

Return code is: 403, ReasonPhrase: Forbidden

The repository rejected the request (403). Your credentials may be valid, but you are not authorized for that repository/path or operation.

Code: PROXY_AUTH_REQUIRED_407

407 Proxy Authentication Required

Maven is using an HTTP proxy to reach repositories, but the proxy requires authentication and Maven is not configured with valid proxy credentials.

Code: NO_PLUGIN_FOUND_FOR_PREFIX

No plugin found for prefix

Maven cannot map that plugin prefix to a real plugin artifact, usually because the plugin is undeclared or missing from configured plugin repositories.

Code: PLUGIN_RESOLUTION_FAILURE

Plugin ... or one of its dependencies could not be resolved

Maven could not resolve the plugin or one of its dependencies, usually because plugin repositories, credentials, or network access are wrong.

Code: LOCAL_REPOSITORY_PERMISSION_DENIED

Could not create local repository

Maven cannot write to the local repository directory (`~/.m2/repository` by default), usually due to permissions or a read-only filesystem.

Code: CHECKSUM_VALIDATION_FAILED

Checksum validation failed

Maven downloaded the artifact, but checksum verification failed, usually because the file is corrupted or a repository or proxy served different bytes.

Code: DEFAULT_HTTP_BLOCKER

Blocked mirror for repositories (maven-default-http-blocker)

Maven 3.8.1 and newer refuse insecure HTTP repository URLs and route them through the built-in `maven-default-http-blocker` mirror.

Code: POM_MISSING

The POM for <artifact> is missing, no dependency information available

Maven located a JAR coordinate, but could not download the corresponding POM, so it cannot determine transitive dependencies or metadata for that artifact.

Code: UNKNOWN_HOST_EXCEPTION

UnknownHostException while downloading dependencies

The machine running Maven could not resolve the repository hostname via DNS, so Maven cannot download artifacts or metadata.

Code: SSL_HANDSHAKE_FAILURE

SSLHandshakeException: Received fatal alert: handshake_failure

The JVM running Maven could not complete the TLS handshake with the repository, so Maven cannot download artifacts over HTTPS.

Code: OFFLINE_MODE

Cannot access <repository> in offline mode

Maven is running with offline mode enabled (`-o` / `--offline`), so it will not contact remote repositories to download missing artifacts.

Code: COMMAND_NOT_FOUND

bash: pip: command not found

Your shell can't find a `pip` executable on `PATH` (or you're using an environment where `pip` is intentionally not installed).

Code: WINDOWS_NOT_RECOGNIZED

'pip' is not recognized as an internal or external command, operable program or batch file.

Windows cannot find the pip command because Python or its Scripts directory is missing from PATH, or pip was not installed correctly.

Code: EXTERNALLY_MANAGED_ENVIRONMENT

error: externally-managed-environment

Your OS Python is marked as "externally managed" (PEP 668), so pip refuses to modify the system environment outside a virtual environment.

Code: NO_MODULE_NAMED_PIP

ModuleNotFoundError: No module named 'pip'

Python cannot import pip because pip is not installed in that interpreter, the environment is broken, or you are using the wrong Python executable.

Code: UNKNOWN_COMMAND

ERROR: unknown command "update" (and "upgrade")

pip does not have `update` or `upgrade` subcommands. Upgrading packages is done with `pip install --upgrade ...`.

Code: NO_REQUIREMENT_GIVEN

ERROR: You must give at least one requirement to install (see "pip help install")

pip install failed because no package, requirements file, wheel, or local path was provided, so pip had nothing to install.

Code: OLD_SCRIPT_WRAPPER

WARNING: pip is being invoked by an old script wrapper. This will fail in a future version of pip.

You're running pip through an outdated entrypoint script. It still works today, but it can break after pip upgrades.

Code: REQUIREMENTS_FILE_NOT_FOUND

ERROR: Could not open requirements file: [Errno 2] No such file or directory: 'requirements.txt'

pip was asked to install from a requirements file path that does not exist (wrong filename, wrong directory, or missing checkout).

Code: INVALID_REQUIREMENT

ERROR: Invalid requirement: ... (requirement spec parse error)

pip could not parse a requirement specifier (malformed version constraint, quotes/smart-quotes, comments, or an invalid line in a requirements file).

Code: DIRECTORY_NOT_INSTALLABLE

ERROR: Directory '.' is not installable. Neither 'setup.py' nor 'pyproject.toml' found.

You asked pip to install from a local directory or sdist, but it doesn't contain standard Python packaging metadata (`pyproject.toml` or `setup.py`).

Code: NO_MATCHING_DISTRIBUTION

ERROR: No matching distribution found (and "Could not find a version that satisfies the requirement")

pip could not find any installable release that matches your requirement and your environment (Python version, OS/architecture, and index configuration).

Code: REQUIRES_PYTHON_MISMATCH

ERROR: Package '<pkg>' requires a different Python ... (Requires-Python mismatch)

The package (or one of its dependencies) declares a `Requires-Python` range that excludes the Python interpreter you're using.

Code: DEPENDENCY_CONFLICT

ERROR: ResolutionImpossible (conflicting dependencies)

pip found conflicting dependency constraints and could not choose a set of package versions that satisfies every requirement.

Code: INSTALLED_PACKAGES_CONFLICT

ERROR: pip's dependency resolver does not currently take into account all the packages that are installed.

Your environment is already inconsistent. pip installed or upgraded something, but the full installed set now contains version conflicts.

Code: SUBPROCESS_EXITED_WITH_ERROR

error: subprocess-exited-with-error

pip delegated part of the install to an external build step (PEP 517 backend or legacy `setup.py`) and that subprocess failed.

Code: FAILED_TO_BUILD_WHEELS

ERROR: Failed to build installable wheels for some pyproject.toml based projects

pip attempted to build a wheel from a PEP 517 project, but the wheel build failed and pip cannot install it without a wheel.

Code: BUILD_TOOLCHAIN_MISSING

Build toolchain missing (gcc / Python.h / MSVC / Rust)

pip is building a package from source, but your system is missing a required toolchain (C/C++ compiler, Python headers, MSVC Build Tools, or Rust).

Code: PERMISSION_DENIED

ERROR: Could not install packages due to an OSError: [Errno 13] Permission denied

pip tried to write into a directory you don't have permission to modify (often system site-packages or a protected install directory).

Code: NO_SPACE_LEFT_ON_DEVICE

Could not install packages due to an EnvironmentError: [Errno 28] No space left on device

The machine ran out of disk space while pip was downloading/building/installing packages (often in the temp directory or cache).

Code: CACHE_DIR_NOT_OWNED

The directory '.../.cache/pip/...' is not owned by the current user and the cache has been disabled.

pip detected that its cache directory is owned by a different user (often because pip was previously run with `sudo`), so it disables caching for safety.

Code: SSL_MODULE_NOT_AVAILABLE

pip is configured with locations that require TLS/SSL, however the ssl module in Python is not available.

Your Python was built or installed without SSL support, so pip cannot make HTTPS requests to package indexes like PyPI.

Code: NETWORK_RETRIES_TIMEOUTS

WARNING: Retrying (...) after connection broken by ... (timeouts / proxy / SSL negotiation)

pip is repeatedly failing to reach the package index due to network timeouts, proxy issues, or TLS incompatibilities, and it is retrying until it gives up.

Code: HASH_MISMATCH

ERROR: THESE PACKAGES DO NOT MATCH THE HASHES FROM THE REQUIREMENTS FILE.

You are using hash-checking mode (`--require-hashes`), but the downloaded file's hash doesn't match, or some requirements are missing hashes.

Code: RECORD_FILE_NOT_FOUND

ERROR: Cannot uninstall <pkg>, RECORD file not found.

pip cannot uninstall a package because it cannot find the installed-files manifest (`RECORD`) in the package metadata.

Code: DISTUTILS_UNINSTALL_BLOCKED

ERROR: Cannot uninstall '<pkg>'. It is a distutils installed project ...

pip will not uninstall the package because distutils or OS packaging installed it without metadata that safely maps files to remove.

Code: CACHE_DESERIALIZATION_FAILED

Cache entry deserialization failed, entry ignored

pip detected a corrupted or incompatible cache entry and ignored it. Installs may be slower or may fail if corruption is widespread.

Code: NU1301

NU1301: Unable to load the service index for source

NuGet could not use one of the configured package sources because the source URL or local path was unavailable, invalid, or unreadable during restore.

Code: NU1302

NU1302: Insecure HTTP service index endpoint detected

NuGet blocked the configured feed because its service index or advertised resources use insecure HTTP instead of HTTPS by default.

Code: NU1101

NU1101: Unable to find package in source

NuGet could not find the requested package ID in any enabled source, which usually means the wrong feed, mapping, name, or credentials.

Code: NU1102

NU1102: Unable to find package with requested version

The package ID exists, but none of the versions available from the enabled feeds satisfy the requested version range or exact pin.

Code: NU1106

NU1106: Unable to satisfy conflicting package version requests

NuGet could not choose one package version because the dependency graph contains incompatible version ranges that cannot be satisfied together.

Code: NU1107

NU1107: Version conflict detected

NuGet found conflicting requested versions of the same package and needs you to pin or upgrade dependencies so the graph converges.

Code: NU1202

NU1202: Package is not compatible with the target framework

The selected package version does not contain lib or ref assets compatible with one of your project’s target frameworks or platforms.

Code: NU1605

NU1605: Detected package downgrade

NuGet resolved a lower version than one dependency path requested, which may break assumptions and is often treated as an error.

Code: NU1608

NU1608: Detected package version outside of dependency constraint

NuGet resolved a package version outside another package’s declared dependency range, and that mismatch may be treated as an error.

Code: NU1011

NU1011: PackageVersion items cannot specify a floating version

With Central Package Management enabled, floating versions in `PackageVersion` are blocked unless explicitly enabled.

Code: NU1903

NU1903: Package has a known high severity vulnerability

NuGet audit data marked a resolved package version as having a known high-severity vulnerability, which may fail restore or CI.

Code: NETSDK1045

NETSDK1045: The current .NET SDK does not support targeting this framework

The .NET SDK selected for this build is older than the project’s target framework, so the SDK cannot build or restore it.

Code: NETSDK1004

NETSDK1004: Assets file not found

The build cannot find project.assets.json from the restore step, so package resolution data is missing for the current project.

Code: NETSDK1022

NETSDK1022: Duplicate items were included

The project explicitly includes files that SDK-style projects already include by default, creating duplicate items.

Code: NETSDK1152

NETSDK1152: Found multiple publish output files with the same relative path

Two files in the publish graph would land at the same relative output path, so the SDK fails instead of overwriting one silently.

Code: NETSDK1147

NETSDK1147: Missing workload for the specified target framework

The project targets a workload-based platform, but the required .NET workload isn’t installed for the current SDK.

Code: NETSDK1005

NETSDK1005 / NETSDK1047: Assets file doesn't have a required target

The existing assets file was restored for a different target framework or runtime identifier than the current build or publish command.

Code: NETSDK1083

NETSDK1083: The specified RuntimeIdentifier is not recognized

The `RuntimeIdentifier` you specified isn’t in the RID graph used by your SDK, so RID-specific resolution fails.

Code: MSB1003

MSB1003: Specify a project or solution file

MSBuild was invoked without a project or solution argument in a directory that contains no buildable project or solution.

Code: MSB4236

MSB4236: The specified SDK could not be found

MSBuild could not resolve the project SDK, such as Microsoft.NET.Sdk, because the required .NET SDK or SDK resolver is unavailable.

Code: MSB3644

MSB3644: The reference assemblies for the target framework were not found

MSBuild cannot find .NET Framework reference assemblies because the targeting pack is missing, the target framework is wrong, or the fallback package is absent.