Error map

OPcache stale code PHP still runs old code after deploy (OPcache not reset)

PHP · layer 4, Application & API

Open the full error page →

Centre: this error. First ring: errors it is linked with (8). 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.

1 · On your device 2 · Network 4 · Application & API 6 · Platform & cloud
OPcache stale code — PHP still runs old code after deploy (OPcache not reset) (PHP)OPcache sta…FileNotFoundException assembly — Could not load file or assembly 'X, Version=…' or one of its dependencies (.NET)FileNotFoundExcepti…Primary script unknown — FastCGI sent in stderr: "Primary script unknown" (PHP)Primary script unkn…module MIME type — Failed to load module script: Expected a JavaScript module script but the server responded with a MIME type of "text/html" (JavaScript)module MIME typeUnexpected token < — SyntaxError: Unexpected token '<' (HTML served instead of JavaScript) (JavaScript)Unexpected token <ChunkLoadError — ChunkLoadError: Loading chunk 123 failed. (JavaScript)ChunkLoadErrorYou must install or update .NET to run this application — The framework 'Microsoft.NETCore.App', version '8.0.0' (x64) was not found. You must install or update .NET to run this application (.NET)You must install or…App Service Application Error — Azure App Service: ":( Application Error" / container didn’t respond to HTTP pings (Azure)App Service Applica…MIME type not executable — Refused to execute script from 'x' because its MIME type ('text/html') is not executable (JavaScript)MIME type not execu…ClassNotFoundException — java.lang.ClassNotFoundException / NoClassDefFoundError (Java)ClassNotFoundExcept…500.30 — HTTP Error 500.30 - ASP.NET Core app failed to start (.NET)500.30NETSDK1045 — error NETSDK1045: The current .NET SDK does not support targeting .NET 8.0. Either target .NET 7.0 or lower, or use a version of the .NET SDK that supports .NET 8.0 (.NET)NETSDK1045403 — HTTP 403 Forbidden (HTTP)403404 — HTTP 404 Not Found (HTTP)404502 — HTTP 502 Bad Gateway (HTTP)502Refused to apply style from — Console: Refused to apply style from 'https://…/style.css' because its MIME type ('text/html') is not a supported stylesheet MIME type (Browser)Refused to apply st…Service worker registration failed — Console: Failed to register a ServiceWorker: A bad HTTP response code (404) was received when fetching the script (Browser)Service worker regi…Failed to find a valid digest in the 'integrity' attribute — Console: Failed to find a valid digest in the 'integrity' attribute for resource … with computed SHA-256 integrity (Browser)Failed to find a va…SyntaxError: JSON — SyntaxError: Unexpected token < in JSON at position 0 (JavaScript)SyntaxError: JSONmissing ) — SyntaxError: missing ) after argument list (JavaScript)missing )already declared — SyntaxError: Identifier 'x' has already been declared (JavaScript)already declaredinvalid selector — DOMException: Failed to execute 'querySelector' on 'Document': 'x' is not a valid selector (JavaScript)invalid selectorCan't resolve 'fs' — Module not found: Can't resolve 'fs' (Next.js / webpack 5) (React)Can't resolve 'fs'Module parse failed — Module parse failed: Unexpected token. You may need an appropriate loader to handle this file type (React)Module parse failedUnsupportedClassVersionError — java.lang.UnsupportedClassVersionError: class file version 61.0, this version of the Java Runtime only recognizes up to 55.0 (Java)UnsupportedClassVer…System.Drawing.Common is not supported — PlatformNotSupportedException: System.Drawing.Common is not supported on this platform (.NET)System.Drawing.Comm…CrashLoopBackOff — Kubernetes: CrashLoopBackOff (Kubernetes)CrashLoopBackOffNo job functions found — Azure Functions: No job functions found. Try making your job classes and methods public / Error indexing method (Azure)No job functions fo…DevTools failed to load source map — DevTools: Failed to load source map — Could not load content for https://…/app.js.map: HTTP error: status code 404 (Browser)DevTools failed to …

Directly related (8)

FileNotFoundException assembly.NET

Could not load file or assembly 'X, Version=…' or one of its dependencies

The runtime couldn’t find or load a referenced DLL — missing from the output, wrong version, or wrong platform (x86/x64).

Primary script unknownPHP

FastCGI sent in stderr: "Primary script unknown"

Nginx passed a script path to PHP-FPM that PHP-FPM couldn’t find — usually a wrong SCRIPT_FILENAME or root.

module MIME typeJavaScript

Failed to load module script: Expected a JavaScript module script but the server responded with a MIME type of "text/html"

A or dynamic import got HTML back instead of JavaScript.

Unexpected token <JavaScript

SyntaxError: Unexpected token '<' (HTML served instead of JavaScript)

The browser loaded a .js file but received HTML (an error page or the SPA index.html).

ChunkLoadErrorJavaScript

ChunkLoadError: Loading chunk 123 failed.

A lazily loaded JavaScript chunk couldn’t be downloaded — usually because a new deployment removed the old hashed files.

You must install or update .NET to run this application.NET

The framework 'Microsoft.NETCore.App', version '8.0.0' (x64) was not found. You must install or update .NET to run this application

The machine doesn’t have the .NET runtime version the app was built for (framework-dependent deployment).

App Service Application ErrorAzure

Azure App Service: ":( Application Error" / container didn’t respond to HTTP pings

App Service started your app but it crashed or never listened on the expected port.

MIME type not executableJavaScript

Refused to execute script from 'x' because its MIME type ('text/html') is not executable

The browser fetched a script but the server labelled it text/html (usually an error page), so it refused to run it.

Two steps away (20)

ClassNotFoundExceptionJava

java.lang.ClassNotFoundException / NoClassDefFoundError

The JVM couldn’t find a class on the classpath at runtime.

500.30.NET

HTTP Error 500.30 - ASP.NET Core app failed to start

IIS/Azure’s ASP.NET Core Module launched your app but it crashed during startup.

NETSDK1045.NET

error NETSDK1045: The current .NET SDK does not support targeting .NET 8.0. Either target .NET 7.0 or lower, or use a version of the .NET SDK that supports .NET 8.0

The installed .NET SDK is older than the project’s TargetFramework.

403HTTP

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…

404HTTP

HTTP 404 Not Found

The server can’t find anything at the requested URL.

502HTTP

HTTP 502 Bad Gateway

A proxy or gateway (Nginx, load balancer, CDN) got an invalid response — or no response — from the upstream server behind it.

Refused to apply style fromBrowser

Console: Refused to apply style from 'https://…/style.css' because its MIME type ('text/html') is not a supported stylesheet MIME type

The stylesheet URL returned something that is not CSS — usually a 404/HTML error page — and `X-Content-Type-Options: nosniff` mak…

Service worker registration failedBrowser

Console: Failed to register a ServiceWorker: A bad HTTP response code (404) was received when fetching the script

The browser could not fetch, parse or install the service worker script, or the page is not allowed to register one (HTTPS and sc…

Failed to find a valid digest in the 'integrity' attributeBrowser

Console: Failed to find a valid digest in the 'integrity' attribute for resource … with computed SHA-256 integrity

A `` or `` with an `integrity` hash was blocked because the downloaded file does not match that hash.

SyntaxError: JSONJavaScript

SyntaxError: Unexpected token < in JSON at position 0

`JSON.parse()` / `response.json()` received something that isn’t JSON — very often an HTML error page.

missing )JavaScript

SyntaxError: missing ) after argument list

A function call’s parentheses are unbalanced — often an unescaped quote or a missing comma/plus.

already declaredJavaScript

SyntaxError: Identifier 'x' has already been declared

The same let/const/class name was declared twice in the same scope.

invalid selectorJavaScript

DOMException: Failed to execute 'querySelector' on 'Document': 'x' is not a valid selector

The CSS selector string is invalid — often an ID starting with a digit or containing special characters.

Can't resolve 'fs'React

Module not found: Can't resolve 'fs' (Next.js / webpack 5)

A Node.js built-in (fs, path, crypto, net) is imported into code that runs in the browser bundle.

Module parse failedReact

Module parse failed: Unexpected token. You may need an appropriate loader to handle this file type

Webpack found syntax it can’t parse because no loader is configured for that file (JSX, TypeScript, CSS, or modern syntax in node…

UnsupportedClassVersionErrorJava

java.lang.UnsupportedClassVersionError: class file version 61.0, this version of the Java Runtime only recognizes up to 55.0

Code compiled for a newer Java version is running on an older JVM.

System.Drawing.Common is not supported.NET

PlatformNotSupportedException: System.Drawing.Common is not supported on this platform

Since .NET 6, System.Drawing.Common only works on Windows; on Linux/macOS (including Docker) it throws.

CrashLoopBackOffKubernetes

Kubernetes: CrashLoopBackOff

The container starts, crashes (or exits), and Kubernetes keeps restarting it with increasing back-off delays.

No job functions foundAzure

Azure Functions: No job functions found. Try making your job classes and methods public / Error indexing method

The Functions host started but couldn’t discover or index any functions — wrong project structure, extension/binding problems or…

DevTools failed to load source mapBrowser

DevTools: Failed to load source map — Could not load content for https://…/app.js.map: HTTP error: status code 404

DevTools could not download the `.map` file that a script or stylesheet points to, so you see minified code instead of your sourc…

Map another error

Popular: 4035004000xC000007BTypeErrorCritical error404NullPointerException