Error Code Troubleshooting
Identify, understand, and fix technical errors. We break down cryptic codes into clear causes and actionable solutions for developers.
Database Errors
PostgreSQL Deadlock Detected
The current transaction was chosen as a deadlock victim and rolled back.
Database Connection Pool Exhausted
All connections in the database connection pool are in use and no new connections can be acquired.
PostgreSQL Unique Constraint Violation
An INSERT or UPDATE attempted to create a duplicate value in a column with a UNIQUE constraint.
PostgreSQL Foreign Key Violation
An INSERT or UPDATE references a value that does not exist in the referenced table.
Redis Connection Error
The application cannot connect to the Redis server.
Docker Errors
Git Errors
Git Merge Conflict
Two branches have made conflicting changes to the same part of a file.
Git Detached HEAD State
HEAD points directly to a commit instead of a branch, meaning new commits will not be on any branch.
Git Push Rejected (Non-Fast-Forward)
The remote branch has commits that your local branch does not have, preventing a fast-forward push.
HTTP Errors
Bad Request
The server cannot process the request due to something that is perceived to be a client error.
Unauthorized
The request has not been applied because it lacks valid authentication credentials for the target resource.
Forbidden
The server understood the request but refuses to authorize it.
Not Found
The server cannot find the requested resource.
Unprocessable Entity
The server understands the request but cannot process it due to semantic errors.
Too Many Requests
The user has sent too many requests in a given amount of time (rate limiting).
Internal Server Error
The server encountered an unexpected condition that prevented it from fulfilling the request.
Bad Gateway
The server, acting as a gateway or proxy, received an invalid response from an upstream server.
Service Unavailable
The server is temporarily unable to handle the request due to overload or maintenance.
SSL Certificate Expired
The SSL/TLS certificate for the server has expired.
Node.js Errors
EADDRINUSE, Address Already in Use
The port your application is trying to bind to is already in use by another process.
ECONNREFUSED, Connection Refused
The connection to a remote host was refused because nothing is listening on the target port.
EACCES, Permission Denied
The process does not have permission to perform the requested operation.
ENOENT. No Such File or Directory
The file or directory specified in the operation does not exist.
ETIMEDOUT, Connection Timed Out
The connection attempt timed out before a response was received.
Java NullPointerException
An attempt was made to use a null reference where an object is required.
OAuth Errors
OAuth 2.0 Invalid Grant
The provided authorization grant or refresh token is invalid, expired, revoked, or does not match the redirection URI.
JWT TokenExpiredError
The JWT has passed its expiration time (exp claim).
JWT Invalid Signature
The JWT signature does not match the expected signature for the given header and payload.
OAuth 2.0 Invalid Client
The client authentication failed, the client_id or client_secret is invalid.
Python Errors
Python ImportError / ModuleNotFoundError
Python cannot find or import the specified module.
Python KeyError
A dictionary key does not exist.
Python TypeError
An operation is applied to an object of an inappropriate type.
Python AttributeError
An object does not have the attribute or method you are trying to access.
REST API Errors
CORS, Cross-Origin Request Blocked
The browser blocked a cross-origin request because the server did not include the required CORS headers.
Stripe Rate Limit Exceeded
Too many API requests were made to the Stripe API in a short period.
GraphQL Validation Error
The GraphQL query failed schema validation before execution.
WebSocket Abnormal Closure (Code 1006)
The WebSocket connection was closed abnormally without a proper closing handshake.