Compiler & Runtime Error Triage Guides
Resolve cryptic compiler exceptions, JWT invalid signatures, Docker BuildKit failures, and MySQL syntax errors. Get 2-sentence mechanical root causes, side-by-side verified fixes, and pre-wired interactive debugging sandboxes.
TokenExpiredError: jwt expired
The current Unix timestamp exceeds the numeric value defined in the JWT exp (expiration) claim. Token verification libraries strictly reject expired credentials to prevent replay attacks.
JsonWebTokenError: invalid signature / algorithm mismatch
The cryptographic signature in the third segment of the JWT does not match the computed hash of the header and payload using the provided verification key. This commonly happens when symmetric HS256 secrets are mistakenly used against asymmetric RS256 public keys.
JsonWebTokenError: jwt malformed
The provided string cannot be split into three period-separated Base64URL segments (header.payload.signature). This frequently happens when "Bearer " prefix is included in the verification call or undefined is passed.
ERROR: failed to solve: failed to compute cache key: not found
BuildKit cannot find the file or directory specified in a COPY or ADD instruction relative to the build context. This occurs when relative paths are incorrect or the file is inadvertently ignored in .dockerignore.
permission denied while trying to connect to the Docker daemon socket
The current non-root user lacks read/write permissions to `/var/run/docker.sock`. By default, only the root user and members of the `docker` user group can access the Docker engine socket.
ERROR 1064 (42000): You have an error in your SQL syntax
The MySQL SQL parser encountered an unexpected token or reserved keyword that violates the grammar specification. This frequently occurs when using reserved words like `order`, `groups`, or `rank` as unquoted column names.
ERROR 1040 (08004): Too many connections
Active client connections to the MySQL server have reached the configured `max_connections` ceiling. All subsequent TCP connection attempts are rejected with Error 1040.
error:1e08010c:decoder routines::unsupported / bad decrypt
OpenSSL 3.0 deprecated legacy cryptographic algorithms like RC4, DES, and MD5-based key derivation by default. When an application attempts to parse a legacy encrypted key without modern AES-256-GCM encryption, it fails with bad decrypt.
Error: certificate has expired (CERT_HAS_EXPIRED)
The TLS certificate presented by the remote server has passed its `notAfter` validity expiration date. Modern HTTP clients and web browsers immediately terminate TLS handshakes to protect users from stale keys.
Type 'X' is not assignable to type 'Y' (TS2322)
A variable or function parameter was assigned a value whose structural type conflicts with the declared type contract. TypeScript’s static analyzer rejects the assignment to prevent runtime property access failures.
Error: Event handlers cannot be passed to Client Component props
A Server Component attempted to pass a non-serializable function or event handler (such as `onClick` or `onChange`) across the boundary into a Client Component. Server Component props must be JSON-serializable to support streaming HTML over the network.