Error map
login_required OIDC Error: login_required / interaction_required / consent_required (silent authentication failed)
Authentication · layer 4, Application & API
Centre: this error. First ring: errors it is linked with (12). Outer ring: what those are linked with. Colours show the layer of a request each error belongs to. Click any dot to re-centre the map on it; hover to follow its connections. The centre dot opens the error page.
Directly related (12)
OAuth 2.0 Error: invalid_grant
The authorization code, refresh token or credentials sent to the token endpoint are invalid, expired, already used or were issued…
Passport.js: Error: Failed to serialize user into session
Passport logged a user in but there’s no serializeUser function (or it didn’t call done), so the session can’t store the user.
Warning: session_start(): Session cannot be started after headers have already been sent
session_start() ran after output was sent, so PHP can’t set the session cookie.
Warning: session_start(): open(/var/lib/php/sessions/sess_x, O_RDWR) failed: Permission denied
PHP can’t write session files to the configured session.save_path.
InvalidOperationException: Session has not been configured for this application or request
Code used HttpContext.Session, but session services/middleware aren’t registered — or UseSession runs after the endpoint that nee…
OIDC Error: nonce mismatch / ID token nonce did not match / unexpected nonce
The nonce inside the ID token doesn’t match the one the app stored — the replay protection check failed.
AWS: ExpiredToken — The security token included in the request is expired
Temporary AWS credentials (STS/SSO/assumed role) have expired.
WordPress login: Error: Cookies are blocked or not supported by your browser. You must enable cookies to use WordPress.
WordPress’s test cookie wasn’t returned on login — often a siteurl/home or domain mismatch, caching of wp-login.php, or headers a…
OAuth callback error: state mismatch / Unable to verify authorization request state / State cookie was missing
The state value returned to the callback doesn’t match what the app stored before redirecting — the CSRF protection for OAuth fai…
OAuth 2.0 Error: access_denied (The user or authorization server denied the request)
The authorization request was refused — the user clicked Cancel/Deny on the consent screen, or a policy denied access.
HTTP 431 Request Header Fields Too Large
The request headers — almost always cookies — exceed the server’s size limit.
ForbiddenError: invalid csrf token (EBADCSRFTOKEN)
The request’s CSRF token is missing or doesn’t match the token tied to the user’s session/cookie.
Two steps away (35)
Azure AD (Entra ID): AADSTS700016 Application not found in the directory
The client ID in your sign-in request doesn’t exist in the tenant you’re authenticating against.
HTTP 400 Bad Request
The server could not understand the request because its syntax, headers or body are malformed or invalid.
HTTP 401 Unauthorized
The request has no valid authentication credentials — you need to log in or send a valid token.
This Set-Cookie was blocked because it had the "SameSite=Lax" attribute but came from a cross-site response / SameSite=None requires Secure
The browser refused to store or send an auth/session cookie because of SameSite or Secure rules — so logins don’t “stick” across…
bcrypt error: Illegal arguments: undefined, string / data and salt arguments required / data and hash arguments required
bcrypt.compare/hash received undefined — the password field or stored hash wasn’t passed.
Warning: Cannot modify header information - headers already sent
You called `header()`, `setcookie()` or `session_start()` after output had already been sent to the browser.
CORS Error: No 'Access-Control-Allow-Origin' header is present
The browser blocked a cross-origin request because the server’s response didn’t include the CORS headers allowing your site’s ori…
HTTP 411 Length Required
The server refuses a request with a body but no Content-Length header.
Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?
The docker CLI can’t talk to the Docker engine — it isn’t running, or your user can’t access the socket.
HTTP 403 Forbidden
The server understood the request but refuses to authorize it — you (or the server process) are not allowed to access this resour…
OAuth 2.0 Error: invalid_scope / insufficient_scope
The requested scope is unknown or not allowed for this client — or the token lacks the scope the API endpoint requires.
ASP.NET Core: The CORS protocol does not allow specifying a wildcard (any) origin and credentials at the same time
The CORS policy uses AllowAnyOrigin() together with AllowCredentials(), which browsers forbid.
AmbiguousMatchException: The request matched multiple endpoints. Matches: X, Y
Two controller actions or minimal API endpoints have the same route and HTTP method.
ASP.NET Core: The antiforgery token could not be decrypted / The required antiforgery cookie is not present (400 Bad Request)
Form POST failed antiforgery validation — the token is missing, the cookie is missing, or Data Protection keys changed so old tok…
Webhook signature verification failed (Stripe, Razorpay, GitHub…)
Your endpoint computed a different HMAC signature than the one the provider sent, so the webhook is rejected.
invalid_token: The access token is invalid (JsonWebTokenError: invalid signature / jwt malformed)
A token was sent but the server couldn’t verify it — bad signature, malformed, revoked, or issued for another audience or environ…
java.lang.SecurityException: Permission Denial ... requires android.permission.X
The app called an API that needs a permission it hasn’t declared or the user hasn’t granted at runtime.
AWS S3: AccessDenied (403) when calling GetObject / PutObject
An IAM policy, bucket policy, ACL/ownership setting, Block Public Access or KMS key policy denied the S3 request.
kubectl: The connection to the server localhost:8080 was refused — did you specify the right host or port?
kubectl has no usable kubeconfig, so it falls back to localhost:8080 — or the cluster API server is unreachable.
AWS: Unable to locate credentials / Could not load credentials from any providers
The AWS CLI/SDK found no credentials in any place it looks — env vars, profile files, SSO cache or an instance/task role.
WordPress: ERR_TOO_MANY_REDIRECTS / redirected you too many times on wp-admin or the whole site
WordPress and the server/proxy keep redirecting to each other — usually siteurl/home mismatch (http vs https, www vs non-www) or…
WordPress: 404 Not Found on every page except the homepage (permalinks / .htaccess / Nginx rules)
Pretty permalinks aren’t being routed to index.php — .htaccess is missing/ignored (Apache) or Nginx lacks try_files.
WordPress: 403 Forbidden on wp-admin, wp-login.php or admin-ajax.php
The server or a security layer refused access to WordPress admin URLs — file permissions, a security plugin/WAF rule, ModSecurity…
Laravel: 419 Page Expired (CSRF token mismatch)
Laravel rejected a POST because the CSRF token was missing, expired or didn’t match the session.
Forbidden (403) CSRF verification failed. Request aborted.
Django rejected a POST because the CSRF token was missing, wrong, or the request origin isn’t trusted.
OAuth PKCE error: invalid_grant — PKCE verification failed / code_verifier does not match code_challenge / code_challenge required
The code_verifier sent to the token endpoint doesn’t match the code_challenge from the authorize request, or PKCE is required but…
PERMISSION_DENIED: The caller does not have permission (insufficient permissions)
You are authenticated, but your identity isn’t allowed to perform this action on this resource.
AADSTS65001: The user or administrator has not consented to use the application
The app needs permissions that haven’t been granted for this user or tenant.
Google OAuth: Error 403: access_denied — The developer hasn't given you access to this app / has not completed the Google verification process
The Google OAuth app is in “Testing” publishing status and the signing-in account isn’t listed as a test user.
HTTP 413 Content Too Large (Request Entity Too Large)
The request body is bigger than the server is willing to accept — usually a file upload over the configured limit.
HTTP 414 URI Too Long
The request URL (usually the query string) is longer than the server will accept.
Chrome: This page isn’t working — example.com is unable to handle this request. ERR_HTTP2_PROTOCOL_ERROR
The HTTP/2 connection broke a protocol rule — a server, proxy or CDN sent an invalid or oversized frame/header, or closed the str…
Error creating: pods is forbidden: violates PodSecurity "restricted:latest": allowPrivilegeEscalation != false ...
The namespace enforces a Pod Security Standard (baseline/restricted) and the pod spec breaks one of its rules.
WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! (ssh host key changed)
The server’s SSH host key differs from the one saved in ~/.ssh/known_hosts — usually because the server was rebuilt or the IP was…
The following signatures couldn't be verified because the public key is not available: NO_PUBKEY
apt can’t verify a repository’s signature because the repo’s signing key isn’t installed (or has expired/rotated).
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