Error Code Lookup

HTTP 400 Bad Request The server could not understand the request. HTTP 401 Unauthorized Authentication is required and has failed or was not provided. HTTP 403 Forbidden The server understood the request but refuses to authorize it. HTTP 404 Not Found The requested page or resource does not exist on the server. HTTP 405 Method Not Allowed The server recognizes the request method but the target resource does not allow it. HTTP 408 Request Timeout The server timed out waiting for the client to finish sending the request. HTTP 409 Conflict The request conflicts with the current state of the target resource. HTTP 410 Gone The requested resource is permanently gone and no forwarding address is available. HTTP 413 Payload Too Large The request body is larger than the server is willing or able to process. HTTP 415 Unsupported Media Type The server refuses the request because the payload's media type is unsupported. HTTP 422 Unprocessable Content The server understood the request and its syntax but cannot process the contained instructions. HTTP 429 Too Many Requests The client has sent too many requests in a given amount of time and is being rate-limited. HTTP 431 Request Header Fields Too Large The server refuses the request because its header fields are too large, individually or collectively. HTTP 451 Unavailable For Legal Reasons The resource is unavailable because of a legal demand to block access to it. HTTP 500 Internal Server Error A generic server-side failure while processing the request. HTTP 501 Not Implemented The server does not support the functionality required to fulfill the request. HTTP 502 Bad Gateway A gateway or proxy received an invalid response from the upstream server. HTTP 503 Service Unavailable The server is temporarily unable to handle the request. HTTP 504 Gateway Timeout A gateway did not receive a timely response from the upstream server. HTTP 301 Moved Permanently The resource has permanently moved to a new URL and clients should use the new location from now on. HTTP 302 Found The resource is temporarily available at a different URL while the original URL remains canonical. HTTP 304 Not Modified The resource has not changed since the client's cached copy, so no body is returned. HTTP 307 Temporary Redirect The resource is temporarily at a different URL and the request method and body must be preserved on redirect. HTTP 308 Permanent Redirect The resource has permanently moved and the request method and body must be preserved on redirect. Windows 0x80070005 Access denied — the operation lacks the required permissions. Windows 0x80070057 The parameter is incorrect — an operation received an invalid argument. Windows 0x8007007B The filename, directory name or volume label syntax is incorrect. Windows 0x80004005 Unspecified error — the catch-all Windows failure code. Windows 0xC0000005 Access violation — a program read or wrote memory it does not own. Windows 0x80070002 The system cannot find the file specified. Windows 0x800F0922 A Windows update or optional feature failed to install (0x800F0922). Windows 0x80073712 Windows Update failed because a required update component is missing or corrupted (0x80073712). Windows 0x80070643 An update installation failed with a fatal error, most often a .NET Framework or security-intelligence update (0x80070643). Windows 0x80072EE2 Windows Update timed out while trying to connect to the update servers (0x80072EE2). Windows CRITICAL_PROCESS_DIED Blue screen: a process critical to Windows terminated unexpectedly. Windows KERNEL_SECURITY_CHECK_FAILURE Blue screen: the kernel detected corruption of a critical data structure. Windows IRQL_NOT_LESS_OR_EQUAL A blue-screen stop error (IRQL_NOT_LESS_OR_EQUAL) where a driver or kernel process accessed memory at an invalid IRQL. Windows PAGE_FAULT_IN_NONPAGED_AREA A blue-screen stop error (PAGE_FAULT_IN_NONPAGED_AREA) where the system requested a page of memory that was not present. Windows DPC_WATCHDOG_VIOLATION A blue-screen stop error (DPC_WATCHDOG_VIOLATION) where a driver spent too long at high priority and the watchdog timer expired. Windows SYSTEM_SERVICE_EXCEPTION A blue-screen stop error (SYSTEM_SERVICE_EXCEPTION) triggered by an illegal instruction or memory access in kernel or driver code. Windows INACCESSIBLE_BOOT_DEVICE A blue-screen stop error (INACCESSIBLE_BOOT_DEVICE) where Windows cannot read the disk it should boot from. Windows 0xC000021A A fatal blue-screen stop error (0xC000021A / STATUS_SYSTEM_PROCESS_TERMINATED) where a critical user-mode system process such as winlogon or csrss terminated unexpectedly. Browser & network ERR_CONNECTION_REFUSED The target machine actively refused the connection. Browser & network ERR_CONNECTION_TIMED_OUT The connection attempt got no answer in time. Browser & network ERR_CONNECTION_RESET The connection to the server was reset before the response completed (ERR_CONNECTION_RESET). Browser & network ERR_CONNECTION_CLOSED The server closed the connection unexpectedly while the browser was loading the page (ERR_CONNECTION_CLOSED). Browser & network ERR_NAME_NOT_RESOLVED The domain name could not be translated into an IP address. Browser & network DNS_PROBE_FINISHED_NXDOMAIN DNS answered: this domain does not exist. Browser & network ERR_INTERNET_DISCONNECTED The browser has no active internet connection (ERR_INTERNET_DISCONNECTED). Browser & network ERR_TIMED_OUT The server took too long to respond and the request timed out (ERR_TIMED_OUT). Browser & network ERR_ADDRESS_UNREACHABLE The browser could not reach the server's IP address (ERR_ADDRESS_UNREACHABLE). Browser & network ERR_SSL_PROTOCOL_ERROR The secure connection could not be established. Browser & network NET::ERR_CERT_AUTHORITY_INVALID The site’s certificate is not signed by a trusted authority. Browser & network NET::ERR_CERT_DATE_INVALID The site's TLS certificate is expired or not yet valid (NET::ERR_CERT_DATE_INVALID). Browser & network NET::ERR_CERT_COMMON_NAME_INVALID The site's TLS certificate does not match the domain being visited (NET::ERR_CERT_COMMON_NAME_INVALID). Browser & network ERR_TOO_MANY_REDIRECTS The page redirected so many times the browser gave up. Browser & network ERR_EMPTY_RESPONSE The server closed the connection without sending any data. Browser & network ERR_CACHE_MISS The browser needed to re-submit a form but the cached data was gone. Browser & network ERR_QUIC_PROTOCOL_ERROR The QUIC/HTTP-3 connection failed. Browser & network ERR_BLOCKED_BY_CLIENT A browser extension or client-side tool blocked the request (ERR_BLOCKED_BY_CLIENT). Browser & network ERR_FILE_NOT_FOUND A locally referenced file could not be found (ERR_FILE_NOT_FOUND). JavaScript TypeError: Cannot read properties of undefined Code tried to read a property of undefined (or null). JavaScript TypeError: Cannot read properties of null Code tried to read a property or call a method on a value that is null. JavaScript ReferenceError: x is not defined A variable or function name is used but was never declared in scope. JavaScript TypeError: x is not a function Code tried to call something as a function that is not a function. JavaScript SyntaxError: Unexpected token The JavaScript parser hit a character it did not expect. JavaScript SyntaxError: Unexpected end of JSON input JSON.parse() received an empty or truncated string and could not finish parsing. JavaScript RangeError: Maximum call stack size exceeded The call stack limit was exceeded. JavaScript Uncaught (in promise) A promise rejected and nothing caught the error. JavaScript Blocked by CORS policy: No 'Access-Control-Allow-Origin' The browser blocked a cross-origin request the server did not allow. JavaScript TypeError: Failed to fetch fetch() could not complete the network request. JavaScript TypeError: Assignment to constant variable Code tried to reassign a variable that was declared with const. JavaScript TypeError: Cannot convert undefined or null to object An operation that expects an object (such as Object.keys or Object.assign) received null or undefined. JavaScript SyntaxError: Cannot use import statement outside a module An ES import statement was used in a file that is not treated as an ES module. JavaScript React: Hydration failed React's server-rendered HTML did not match what the client rendered during hydration. JavaScript TypeError: x.map is not a function Code called .map() on a value that is not an array. Python ModuleNotFoundError: No module named 'x' Python could not find any installed module matching the name you tried to import. Python ImportError: cannot import name The module was found, but the specific name you asked to import from it does not exist in it. Python IndentationError: unexpected indent A line is indented more than the surrounding block allows, so Python cannot parse the structure. Python TabError: inconsistent use of tabs and spaces A block mixes tabs and spaces for indentation in a way Python cannot resolve unambiguously. Python SyntaxError: invalid syntax The interpreter hit code that is not valid Python and could not be parsed. Python NameError: name 'x' is not defined You referenced a name that has not been defined in the current scope. Python TypeError: unsupported operand type An operator was applied to operands whose types it does not support together. Python TypeError: object is not callable You tried to call something with () that is not a function or callable. Python ValueError: invalid literal for int() int() received a string that does not represent a valid base-10 integer. Python KeyError You looked up a dictionary key that does not exist. Python IndexError: list index out of range You accessed a list position that is beyond the range of its elements. Python AttributeError: 'NoneType' object has no attribute You accessed an attribute or method on a value that is None instead of the expected object. Python TypeError: 'NoneType' object is not subscriptable You used indexing or slicing (e.g. x[0]) on a value that is None. Python ZeroDivisionError: division by zero A division or modulo operation used zero as the divisor. Python FileNotFoundError: No such file or directory Python could not find the file or directory at the path you gave. Python RecursionError: maximum recursion depth exceeded A function called itself too many times and exceeded Python's recursion depth limit. Python UnicodeDecodeError Bytes could not be decoded into text using the assumed character encoding. Python UnboundLocalError: local variable referenced before assignment A local variable was read before it was assigned inside the function. Python IndexError: string index out of range You accessed a character position beyond the length of the string. Python json.decoder.JSONDecodeError: Expecting value The JSON parser expected a value but the input was empty or not valid JSON. Python PermissionError: Permission denied The operating system refused the file or directory operation because of insufficient permissions. Python pip: command not found The shell could not locate a 'pip' executable on your PATH. Python TypeError: argument of type is not iterable A membership test with 'in' was used on a value that is not iterable. Python TypeError: string indices must be integers A string was indexed with a non-integer, so Python rejected the subscript. PHP Allowed memory size of N bytes exhausted The script tried to use more memory than PHP allows. PHP Maximum execution time exceeded The script ran longer than PHP’s time limit and was killed. PHP Call to undefined function The script called a function that does not exist. PHP Call to undefined method Code called a method that does not exist on the given class or object. PHP Call to a member function on null Code called a method or accessed a member on a variable that is null. PHP Cannot modify header information — headers already sent Code tried to send an HTTP header after output already started. PHP Class "X" not found PHP could not locate the class being instantiated. PHP Parse error: syntax error, unexpected … PHP could not parse the file. PHP Warning: Undefined array key The code read an array key that does not exist. PHP Warning: Undefined variable Code read a variable that was never defined in the current scope. PHP Warning: Attempt to read property on null Code tried to read an object property on a value that is null. PHP ArgumentCountError: Too few arguments to function A function or method was called with fewer required arguments than it declares. PHP Uncaught TypeError A value of the wrong type was passed to, or returned from, a typed function or operation. PHP White screen of death (blank page) The page renders completely blank because a fatal error was thrown but not displayed. PHP SQLSTATE[HY000] [2002] Connection refused PDO/MySQL could not establish a connection to the database server. Node.js & npm Error: Cannot find module 'x' Node could not locate the module you tried to require or import. Node.js & npm ERR_MODULE_NOT_FOUND An ES module import could not be resolved to a file on disk. Node.js & npm ERR_REQUIRE_ESM You used require() on a package that ships only as an ES module. Node.js & npm Error: listen EADDRINUSE: address already in use The port your server tried to bind to is already occupied by another process. Node.js & npm Error: ENOENT: no such file or directory A filesystem operation referenced a file or directory that does not exist. Node.js & npm Error: EACCES: permission denied The process lacks permission to read, write, or bind the requested file, directory, or port. Node.js & npm Error: connect ECONNREFUSED A connection attempt was actively refused because nothing is listening at that host and port. Node.js & npm UnhandledPromiseRejectionWarning A promise rejected and no .catch() or try/catch handled the error. Node.js & npm FATAL ERROR: JavaScript heap out of memory The V8 JavaScript heap grew past its memory limit and Node aborted. Node.js & npm error:0308010C:digital envelope routines::unsupported A legacy crypto/hash routine (often in Webpack 4) is unsupported by OpenSSL 3 in newer Node versions. Node.js & npm npm ERR! code ERESOLVE npm could not resolve a dependency tree because of conflicting peer dependency requirements. Node.js & npm npm ERR! code ELIFECYCLE An npm lifecycle script (such as build, test, or a pre/post hook) exited with a non-zero status. Node.js & npm npm ERR! code ENOENT (package.json) npm could not find a package.json in the current directory. Node.js & npm npm ERR! 404 Not Found The requested package or version was not found in the npm registry. Node.js & npm npm ERR! code EACCES npm was denied filesystem permission, typically when writing to a global directory or its cache. Node.js & npm gyp ERR! build error (node-gyp) node-gyp failed to compile a native (C/C++) addon from source. Node.js & npm npm WARN unmet peer dependency A package declares a peer dependency that is missing or at an unsatisfied version. Node.js & npm npm ERR! code EBADENGINE (unsupported engine) The installed package requires a Node or npm version that does not match your environment. Java java.lang.NullPointerException Code dereferenced a variable that was null, calling a method or accessing a field on nothing. Java java.lang.ClassNotFoundException The JVM could not find a class by name when loading it at runtime. Java java.lang.NoClassDefFoundError A class that was available at compile time could not be loaded at runtime. Java java.lang.OutOfMemoryError: Java heap space The JVM exhausted its heap and could not allocate more objects. Java java.lang.ArrayIndexOutOfBoundsException Code accessed an array element at an index outside the array's valid range. Java java.lang.StringIndexOutOfBoundsException A string operation used a character index outside the string's bounds. Java java.lang.NumberFormatException A string could not be parsed into a numeric type. Java java.lang.ClassCastException An object was cast to a type it is not an instance of. Java java.util.ConcurrentModificationException A collection was structurally modified while it was being iterated. Java java.lang.StackOverflowError The call stack exceeded its size limit, almost always from unbounded recursion. Java UnsupportedClassVersionError A class was compiled for a newer Java version than the JVM running it. Java java.lang.IllegalArgumentException A method was passed an argument that is invalid or out of its accepted range. Java java.lang.IllegalStateException A method was called while the object was in a state that does not allow it. Java java.lang.ArithmeticException: / by zero An integer arithmetic operation attempted to divide by zero. Java java.lang.NoSuchMethodError The JVM could not find a method that existed at compile time. Java Error: Could not find or load main class The java launcher could not locate or load the specified main class. MySQL ERROR 1045: Access denied for user MySQL rejected the username/password combination. MySQL ERROR 2002: Can't connect to local MySQL server The client could not reach the MySQL server at all. MySQL ERROR 1146: Table doesn't exist The query references a table that does not exist in that database. MySQL ERROR 1064: You have an error in your SQL syntax MySQL could not parse the SQL statement. MySQL ERROR 1215: Cannot add foreign key constraint A foreign key constraint could not be created. MySQL ERROR 1452: Cannot add or update a child row (foreign key) MySQL blocked the insert or update because it would violate a foreign key constraint. MySQL ERROR 1040: Too many connections MySQL hit its maximum number of simultaneous connections. MySQL ERROR 2006: MySQL server has gone away The server closed the connection mid-conversation. MySQL ERROR 1054: Unknown column in 'field list' MySQL could not find a column named in the query. MySQL ERROR 1062: Duplicate entry for key MySQL rejected the row because it duplicates a value in a UNIQUE or PRIMARY key. MySQL ERROR 1049: Unknown database MySQL could not find the database name you tried to connect to or use. MySQL ERROR 1366: Incorrect string value MySQL could not store the string because it contains characters the column's charset cannot represent. MySQL ERROR 1698: Access denied (auth_socket) MySQL denied access because the user authenticates via the auth_socket plugin rather than a password. Git fatal: not a git repository Git ran a command outside any repository, so it has no .git directory to work with. Git ! [rejected] ... (non-fast-forward) The push was rejected because the remote branch has commits your local branch does not, so it cannot be fast-forwarded. Git CONFLICT (content): Merge conflict in A merge, rebase, or cherry-pick could not automatically reconcile changes to the same lines of a file. Git Permission denied (publickey) The SSH server rejected the connection because no accepted public key was offered during authentication. Git fatal: The current branch has no upstream branch The current branch has no remote tracking branch, so Git does not know where to push or pull. Git fatal: refusing to merge unrelated histories Git refused to merge two branches that share no common commit ancestor. Git error: Your local changes would be overwritten by merge Git aborted the merge or checkout because it would discard uncommitted changes in your working tree. Git fatal: remote origin already exists A remote named "origin" is already configured, so adding another with the same name fails. Git error: src refspec main does not match any The branch you tried to push does not exist locally, so Git has no source ref to send. Git remote: Authentication failed / password removed The remote rejected your credentials, commonly because password authentication over HTTPS is no longer accepted. Git fatal: Need to specify how to reconcile divergent branches Git 2.27+ will not pull because your local and remote branches have diverged and no reconciliation strategy is configured. Git fatal: detected dubious ownership in repository Git refused to operate on the repository because its files are owned by a different user than the one running Git. Git fatal: Unable to create '.git/index.lock' Git could not create .git/index.lock because a lock file for the index already exists. Git error: pathspec did not match any file(s) Git could not find any file or branch matching the path or name you supplied. Git You are in 'detached HEAD' state HEAD points directly at a specific commit rather than a branch, so new commits are not attached to any branch. Git remote: error: File is too large (GH001) The remote rejected the push because a file exceeds the host's per-file size limit (GitHub caps files at 100 MB). Linux & shell bash: command not found The shell could not locate an executable matching the command name you typed. Linux & shell Permission denied The operating system blocked the action because your user lacks the required permission on the file or resource. Linux & shell No such file or directory A referenced file or directory path does not exist on the filesystem. Linux & shell Segmentation fault (core dumped) A program crashed because it tried to access memory it is not allowed to touch, and a core dump was written. Linux & shell Killed (out of memory) The kernel's out-of-memory killer terminated the process because the system ran out of available memory. Linux & shell No space left on device A write failed because the target filesystem has no free space (or no free inodes) left. Linux & shell cannot execute binary file: Exec format error The kernel could not run the file because its binary format does not match the current CPU architecture or type. Linux & shell Too many open files A process hit the per-process limit on the number of simultaneously open file descriptors. Linux & shell bind: Address already in use A service could not bind to its network port because another process is already listening on it. Linux & shell ssh: connect to host port 22: Connection refused The SSH client reached the host but nothing accepted the connection on port 22. Linux & shell Host key verification failed SSH aborted because the host's presented key does not match the one stored in known_hosts. Linux & shell user is not in the sudoers file Your user is not authorized to run commands via sudo and the attempt was logged. Linux & shell Read-only file system A write was rejected because the filesystem is mounted read-only. Linux & shell bad interpreter: No such file or directory A script could not run because the interpreter named in its shebang line does not exist at that path. Linux & shell error while loading shared libraries The dynamic linker could not find or load a shared library (.so) that the program depends on. Linux & shell Broken pipe A process tried to write to a pipe or socket whose reading end has already been closed. Linux & shell Operation not permitted The kernel denied a privileged operation even though the file may be accessible, because it requires a capability you lack. Email / SMTP SMTP 550: Mailbox unavailable The recipient server rejected the message — mailbox unavailable or policy refusal. Email / SMTP SMTP 554: Transaction failed / rejected as spam The transaction failed — the message was refused, usually as spam. Email / SMTP SMTP 421: Service not available, try again later The receiving server is temporarily unavailable or is rate-limiting you. Email / SMTP SMTP 535: Authentication failed SMTP authentication failed. Email / SMTP SMTP 452: Insufficient system storage The server cannot accept the message right now — storage or quota limits. Email / SMTP SMTP 553: Mailbox name not allowed The mail server rejected the message because the mailbox name in the address is not allowed. Email / SMTP SMTP 501: Syntax error in parameters The server rejected the command because of a syntax error in its arguments or parameters. Email / SMTP SMTP 450: Requested action not taken, mailbox busy The requested mail action was not taken because the mailbox is temporarily unavailable or busy. Email / SMTP SMTP 471: Local error in processing A local error in the receiving server's processing prevented the message from being delivered.