https://fixercode.com Independent reference for web, software, and OS errors with clear explanations and context. en-us Mon, 14 Sep 2026 00:00:00 GMT https://fixercode.com/os/linux/system-errors/error-127 Exit code 127 reports a command the shell could not find in any $PATH directory — the name is missing, misspelled, or not installed. It differs from 126, where the file exists but is not executable, and a script whose shebang names a missing interpreter can also produce it. Mon, 14 Sep 2026 00:00:00 GMT https://fixercode.com/os/linux/system-errors/error-127 https://fixercode.com/os/linux/system-errors/error-11 Signal 11 (SIGSEGV) means the kernel terminated a process for touching memory outside its address space; uncaught, it surfaces as exit code 139. Memory pages carry read, write, and execute permissions; an instruction that violates them or dereferences an unmapped address raises the fault, and the de Mon, 14 Sep 2026 00:00:00 GMT https://fixercode.com/os/linux/system-errors/error-11 https://fixercode.com/os/linux/system-errors/error-128 Exit code 128 on its own means the exit built-in received an argument the shell could not use as an exit status. More often the shell is reporting death by signal: exit statuses above 128 encode signal N as 128 + N, so 130 maps to SIGINT and 137 to SIGKILL. Mon, 14 Sep 2026 00:00:00 GMT https://fixercode.com/os/linux/system-errors/error-128 https://fixercode.com/os/windows/system-errors/error-0x80004005 Windows error 0x80004005 (E_FAIL) is the generic COM 'Unspecified Error' — an operation failed and no more specific code applies. It surfaces across unrelated features: extracting an archive, opening a network share, or starting a VirtualBox virtual machine. The code reports that something failed, n Mon, 14 Sep 2026 00:00:00 GMT https://fixercode.com/os/windows/system-errors/error-0x80004005 https://fixercode.com/software/sql-server/engine-errors/error-2627 Error 2627 is raised when a statement violates a PRIMARY KEY or UNIQUE constraint — the value already exists in the table. The engine cancels the offending statement and rolls it back, so duplicates never land. The message names the exact constraint, which points at the conflicting row or at an ID g Mon, 14 Sep 2026 00:00:00 GMT https://fixercode.com/software/sql-server/engine-errors/error-2627 https://fixercode.com/software/sql-server/engine-errors/error-547 Error 547 means the statement conflicted with a FOREIGN KEY or CHECK constraint and was cancelled to keep related tables consistent. The check runs at the end of statement execution: any row that would orphan a reference or violate a CHECK rule cancels the whole operation. The message names the cons Mon, 14 Sep 2026 00:00:00 GMT https://fixercode.com/software/sql-server/engine-errors/error-547 https://fixercode.com/web/cloudflare/edge-errors/error-522 Error 522 means Cloudflare contacted the origin server, but it never completed the TCP handshake within the 15-second window. The silence is the signature: the server is neither refusing nor answering, which points to overload or a firewall dropping Cloudflare IPs instead of rejecting them. Mon, 14 Sep 2026 00:00:00 GMT https://fixercode.com/web/cloudflare/edge-errors/error-522 https://fixercode.com/web/cloudflare/edge-errors/error-526 Error 526 means the origin's TLS certificate failed validation in Cloudflare's Full (Strict) SSL mode, so the edge refused to connect. Strict mode accepts only certificates from a public Certificate Authority or a Cloudflare Origin CA; expired, self-signed, or wrong-domain certificates all fail it, Mon, 14 Sep 2026 00:00:00 GMT https://fixercode.com/web/cloudflare/edge-errors/error-526 https://fixercode.com/web/cloudflare/edge-errors/error-1020 Error 1020 fires when a firewall rule owned by the site matches the request and blocks it before it reaches the origin server. Such blocks are deliberate configuration rather than an outage: managed WAF rules, country or ASN blocks, and custom user-agent filters all produce this page. Mon, 14 Sep 2026 00:00:00 GMT https://fixercode.com/web/cloudflare/edge-errors/error-1020 https://fixercode.com/web/cloudflare/edge-errors/error-1001 Error 1001 is a DNS failure inside Cloudflare's own zone: the edge could not resolve the requested hostname to an origin IP. That differs from 522, where the name resolved but the origin never answered, and from visitor-side DNS failures, which break every site equally. Mon, 14 Sep 2026 00:00:00 GMT https://fixercode.com/web/cloudflare/edge-errors/error-1001 https://fixercode.com/web/http/status-codes/error-203 Status 203 means the origin returned a success, but an intermediary altered the payload or its metadata before it reached the client. The transformed copy still counts as a successful response; 203 exists so intermediaries can disclose the change instead of passing altered data off as untouched orig Mon, 14 Sep 2026 00:00:00 GMT https://fixercode.com/web/http/status-codes/error-203 https://fixercode.com/web/http/status-codes/error-304 Status 304 Not Modified tells the client that its cached copy is still fresh, so the response carries updated headers but no body. The exchange is the success case of a conditional request: the client sent a validator such as If-None-Match or If-Modified-Since and nothing had changed. Skipping the b Mon, 14 Sep 2026 00:00:00 GMT https://fixercode.com/web/http/status-codes/error-304 https://fixercode.com/web/http/status-codes/error-308 A 308 status code reports a permanent redirect that also preserves the HTTP method, so a POST stays a POST at the new address. It is 301's method-preserving counterpart, mirroring how 307 relates to 302, and search engines treat it as a full permanent-move signal. Mon, 14 Sep 2026 00:00:00 GMT https://fixercode.com/web/http/status-codes/error-308 https://fixercode.com/web/http/status-codes/error-402 Status 402 Payment Required means the service understood the request but gates it behind payment: an exhausted quota or a plan limit. Reserved in 1997 for a micropayment layer that never became standard, it now carries each provider's own billing semantics — declined cards, frozen stores, exhausted Mon, 14 Sep 2026 00:00:00 GMT https://fixercode.com/web/http/status-codes/error-402 https://fixercode.com/web/http/status-codes/error-418 Status 418 is the famous I'm a teapot response: the server deliberately refuses the request as an HTCPCP joke, not because anything failed. It started as RFC 2324, an April Fools' prank from 1998, and became a novelty code that real frameworks implement. Sites and APIs return it on purpose — an east Mon, 14 Sep 2026 00:00:00 GMT https://fixercode.com/web/http/status-codes/error-418 https://fixercode.com/software/docker/core/cannot-connect-to-the-docker-daemon The docker binary is a client that forwards every request to a background daemon over a Unix socket or a TCP endpoint. When the socket file is missing, the daemon process is stopped, or DOCKER_HOST points at an unreachable host, the client prints this message and exits without attempting anything. Sat, 12 Sep 2026 00:00:00 GMT https://fixercode.com/software/docker/core/cannot-connect-to-the-docker-daemon https://fixercode.com/software/docker/core/permission-denied-docker-socket On Linux the daemon listens on /var/run/docker.sock, a Unix socket owned by root with group-write access for the docker group. A shell user outside that group gets a permission denial on connect, and the client reports the failure against the socket path rather than as a generic fault. Sat, 12 Sep 2026 00:00:00 GMT https://fixercode.com/software/docker/core/permission-denied-docker-socket https://fixercode.com/software/docker/core/client-version-too-new Docker ships a versioned Engine API and lets client and daemon negotiate the highest version both understand. When negotiation is bypassed, for example through DOCKER_API_VERSION, or the gap predates the daemon's supported band, the daemon rejects the request with an explicit too-new or too-old line Sat, 12 Sep 2026 00:00:00 GMT https://fixercode.com/software/docker/core/client-version-too-new https://fixercode.com/software/docker/core/manifest-unknown A pull starts by requesting the image manifest, the document listing the image's layers and platforms. When the repository exists but the tag was never pushed, was deleted, or does not include the requesting platform, the registry answers with the manifest unknown condition and the daemon surfaces i Sat, 12 Sep 2026 00:00:00 GMT https://fixercode.com/software/docker/core/manifest-unknown https://fixercode.com/software/docker/core/pull-access-denied Registries deliberately give anonymous callers the same denial for a private repository and a nonexistent one, so the daemon's message lists both possibilities. The pull never starts; no layers download and the local image store stays untouched while credentials are sorted out. Sat, 12 Sep 2026 00:00:00 GMT https://fixercode.com/software/docker/core/pull-access-denied https://fixercode.com/software/docker/core/unauthorized-authentication-required Registry APIs speak token auth: the client fetches a bearer token from an auth service and presents it with each request. When the token is absent, expired, or rejected, the registry returns an unauthorized condition with the authentication required body, and the daemon wraps it in its standard erro Sat, 12 Sep 2026 00:00:00 GMT https://fixercode.com/software/docker/core/unauthorized-authentication-required https://fixercode.com/software/docker/core/denied-requested-access This line is the registry's own denial body, usually attached to a push. Authentication succeeded, yet the account lacks write rights on the namespace, the namespace belongs to someone else, or the repository is read-only. The daemon passes the registry's wording through next to its own envelope. Sat, 12 Sep 2026 00:00:00 GMT https://fixercode.com/software/docker/core/denied-requested-access https://fixercode.com/software/docker/core/toomanyrequests Docker Hub meters image pulls over a six-hour window: unauthenticated users draw from an allowance tied to their IPv4 address or IPv6 /64 subnet, authenticated Personal accounts from a per-user allowance, and paid tiers are unlimited. When a caller is over the limit, the registry answers the manifes Sat, 12 Sep 2026 00:00:00 GMT https://fixercode.com/software/docker/core/toomanyrequests https://fixercode.com/software/docker/core/x509-unknown-authority The daemon validates registry connections against the host trust store plus certificates under the Docker certificates directory. Self-signed or corporate-intercepted registries present a chain the client cannot verify, and the TLS layer rejects the handshake with the unknown-authority wording. Sat, 12 Sep 2026 00:00:00 GMT https://fixercode.com/software/docker/core/x509-unknown-authority https://fixercode.com/software/docker/core/invalid-reference-format Image references follow a grammar: optional registry host, namespace path, repository name, tag, and digest. Uppercase letters in the repository part, stray characters, or an empty name after a host all fail validation locally, and the client rejects the reference before contacting any registry. Sat, 12 Sep 2026 00:00:00 GMT https://fixercode.com/software/docker/core/invalid-reference-format https://fixercode.com/software/docker/core/port-is-already-allocated Publishing a container port asks the daemon to bind that port on the host. Docker tracks allocations across all containers, and when the requested port is already bound by another container the daemon refuses with the port-is-already-allocated wording inside its bind error. Sat, 12 Sep 2026 00:00:00 GMT https://fixercode.com/software/docker/core/port-is-already-allocated https://fixercode.com/software/docker/core/address-already-in-use Underneath the allocator sits the actual system bind. When the address is taken by a process the daemon's bookkeeping does not track, the proxy component reports the kernel's address-already-in-use condition, usually wrapped in the userland proxy line. Sat, 12 Sep 2026 00:00:00 GMT https://fixercode.com/software/docker/core/address-already-in-use https://fixercode.com/software/docker/core/driver-failed-external-connectivity When a container starts, the daemon asks the network driver to wire up published ports for the new endpoint. Failures at that step surface as the driver-failed-programming-external-connectivity line, typically followed by the underlying bind error that caused the wiring to fail. Sat, 12 Sep 2026 00:00:00 GMT https://fixercode.com/software/docker/core/driver-failed-external-connectivity https://fixercode.com/software/docker/core/container-name-already-in-use Container names are unique across the daemon. Creating a new container with a name matching any existing container, running or stopped, is rejected with a conflict message that echoes the holder's ID. Auto-generated names avoid this by construction; explicit names collide on reuse. Sat, 12 Sep 2026 00:00:00 GMT https://fixercode.com/software/docker/core/container-name-already-in-use https://fixercode.com/software/docker/core/no-space-left-on-device Images, container layers, volumes, and logs all live under the daemon's data root. When the backing filesystem hits its limit, layer extraction, log writes, and container creation abort with the kernel's no-space text, so the message reports the filesystem condition rather than a Docker-specific fau Sat, 12 Sep 2026 00:00:00 GMT https://fixercode.com/software/docker/core/no-space-left-on-device https://fixercode.com/software/docker/core/volume-in-use Named volumes persist independently of containers. The volume removal command refuses targets referenced by any container the daemon knows about, listing the referencing container IDs after the volume-is-in-use clause, because deleting a mounted volume would tear data out from live workloads. Sat, 12 Sep 2026 00:00:00 GMT https://fixercode.com/software/docker/core/volume-in-use https://fixercode.com/software/docker/core/network-not-found User-defined networks live in the daemon's registry alongside its built-in peers. Connecting a container, inspecting, or removing a network by a name that was never created, or that a torn-down compose project already deleted, resolves to nothing and returns the not-found condition. Sat, 12 Sep 2026 00:00:00 GMT https://fixercode.com/software/docker/core/network-not-found https://fixercode.com/software/docker/core/pool-overlaps Creating a network with an explicit subnet asks the address manager to reserve that range. When the range intersects any existing network's pool, including the daemon's default address pools, creation is refused with the pool-overlaps message and nothing is created. Sat, 12 Sep 2026 00:00:00 GMT https://fixercode.com/software/docker/core/pool-overlaps https://fixercode.com/software/docker/core/no-such-container Container lookup accepts names and ID prefixes. A reference resolves to nothing after removal, after a typo, or against a different daemon context, and the failing command returns the no-such-container condition instead of operating on any workload. Sat, 12 Sep 2026 00:00:00 GMT https://fixercode.com/software/docker/core/no-such-container https://fixercode.com/software/docker/core/container-is-not-running Exec sessions and attaches require a live process namespace to join. When the target container exited or was only created but never started, the daemon refuses the operation with the container-is-not-running condition and reports the container's actual state around it. Sat, 12 Sep 2026 00:00:00 GMT https://fixercode.com/software/docker/core/container-is-not-running https://fixercode.com/software/docker/core/cannot-remove-a-running-container Container removal implies tearing down the writable layer and network attachments. The daemon refuses to do this for a running process unless the request explicitly forces it, returning the cannot-remove wording that points at the running state as the blocker. Sat, 12 Sep 2026 00:00:00 GMT https://fixercode.com/software/docker/core/cannot-remove-a-running-container https://fixercode.com/software/docker/core/oci-runtime-create-failed Starting a container hands a prepared bundle to an OCI runtime such as runc. Failures inside that step, from invalid mount targets to blocked capabilities, surface as the oci-runtime-create-failed headline followed by the runtime's own diagnostic, appended after a type marker that often reads unknow Sat, 12 Sep 2026 00:00:00 GMT https://fixercode.com/software/docker/core/oci-runtime-create-failed https://fixercode.com/software/docker/core/exec-format-error Images bundle binaries for specific CPU architectures. Running an amd64 binary on an arm64 host, typically after pulling an image without an arm64 manifest entry, reaches the exec syscall, fails with the format error, and the runtime wraps the entrypoint failure in its start error. Sat, 12 Sep 2026 00:00:00 GMT https://fixercode.com/software/docker/core/exec-format-error https://fixercode.com/software/docker/core/oci-runtime-exec-failed Exec into a live container asks the runtime to start an additional process inside the existing namespace. When the requested binary does not exist in the container filesystem, as with minimal distroless images lacking a shell, the runtime reports the exec failure with the not-found path detail. Sat, 12 Sep 2026 00:00:00 GMT https://fixercode.com/software/docker/core/oci-runtime-exec-failed https://fixercode.com/software/docker/core/failed-to-solve BuildKit reports build failures in a solve envelope: the failed-to-solve headline carries the step identifier, the executed command, and the exit code. The envelope is diagnostic structure around an ordinary build-step failure rather than a builder malfunction. Sat, 12 Sep 2026 00:00:00 GMT https://fixercode.com/software/docker/core/failed-to-solve https://fixercode.com/software/docker/core/dockerfile-not-found Every build names its Dockerfile, defaulting to a file of that name in the context root. When the file is absent, renamed, or sits in a subdirectory the flag does not point to, the solve step fails while reading the build definition with the no-such-file wording. Sat, 12 Sep 2026 00:00:00 GMT https://fixercode.com/software/docker/core/dockerfile-not-found https://fixercode.com/software/docker/core/dependency-failed-to-start Compose supports ordering through dependency conditions, including waiting for a service to report healthy. When the dependency's health check never passes within its window, startup aborts with the dependency-failed-to-start line naming the container that stayed unhealthy. Sat, 12 Sep 2026 00:00:00 GMT https://fixercode.com/software/docker/core/dependency-failed-to-start https://fixercode.com/software/docker/core/error-response-from-daemon Most Docker error output begins with this envelope: the CLI received an error response from the Engine API and prints it. The envelope itself carries no diagnosis; the registry, driver, or runtime text following it is the actual condition, from manifest unknown to network not found. Sat, 12 Sep 2026 00:00:00 GMT https://fixercode.com/software/docker/core/error-response-from-daemon https://fixercode.com/os/windows/system-errors/error-0x80070003 0x80070003 is the HRESULT wrapper around Win32 error 3, ERROR_PATH_NOT_FOUND, whose system text reads 'The system cannot find the path specified'. Where error 2 names a missing file, error 3 means the lookup failed earlier — one of the directories on the way to the target does not exist. Windows Upd Sun, 06 Sep 2026 00:00:00 GMT https://fixercode.com/os/windows/system-errors/error-0x80070003 https://fixercode.com/os/windows/system-errors/error-0x8007000e An allocation the memory manager refuses returns 0x8007000E, the HRESULT form of Win32 error 14, ERROR_OUTOFMEMORY — 'Not enough storage is available to complete this operation'. The same value is registered as E_OUTOFMEMORY in Microsoft's common-HRESULT table, so COM callers and interop layers surf Sun, 06 Sep 2026 00:00:00 GMT https://fixercode.com/os/windows/system-errors/error-0x8007000e https://fixercode.com/os/windows/system-errors/error-0x8007001f Hardware that stops answering mid-operation surfaces as 0x8007001F, Win32 error 31, ERROR_GEN_FAILURE — 'A device attached to the system is not functioning'. The upgrade resolution documentation carries the code into setup: 8007001F-0x4000D marks a general device failure during the second-boot phase Sun, 06 Sep 2026 00:00:00 GMT https://fixercode.com/os/windows/system-errors/error-0x8007001f https://fixercode.com/os/windows/system-errors/error-0x80070032 A refusal that names the operation rather than any condition is 0x80070032, Win32 error 50, ERROR_NOT_SUPPORTED — 'The request is not supported'. Unlike an invalid parameter, nothing about the request is malformed; the receiver simply has no implementation behind it, which makes the code a statement Sun, 06 Sep 2026 00:00:00 GMT https://fixercode.com/os/windows/system-errors/error-0x80070032 https://fixercode.com/os/windows/system-errors/error-0x8007007e When the loader walks an import list and one library never resolves, the failure is 0x8007007E, Win32 error 126, ERROR_MOD_NOT_FOUND — 'The specified module could not be found'. The upgrade documentation also records the code in servicing: WSUS environments that synced upgrade metadata before a requ Sun, 06 Sep 2026 00:00:00 GMT https://fixercode.com/os/windows/system-errors/error-0x8007007e https://fixercode.com/os/windows/system-errors/error-0x80070103 Enumerations end quietly — 0x80070103 is the HRESULT for Win32 error 259, ERROR_NO_MORE_ITEMS, whose official text is simply 'No more data is available'. In Windows Update discussions the code is overwhelmingly reported on driver deliveries: the update surface tries to install a driver for a device Sun, 06 Sep 2026 00:00:00 GMT https://fixercode.com/os/windows/system-errors/error-0x80070103 https://fixercode.com/os/windows/system-errors/error-0x8007025d Data that arrives inside a compressed stream and fails its structure checks stops an image apply with 0x8007025D, Win32 error 605, ERROR_BAD_COMPRESSION_BUFFER — 'The specified buffer contains ill-formed data'. The upgrade resolution tables pair the code with extend code 0x2000C and attribute it to Sun, 06 Sep 2026 00:00:00 GMT https://fixercode.com/os/windows/system-errors/error-0x8007025d