Error map
CalledFromWrongThreadException CalledFromWrongThreadException: Only the original thread that created a view hierarchy can touch its views
Android · layer 1, On your device
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.
Directly related (8)
Blazor: An unhandled error has occurred. Reload 🗙
A Blazor component threw an exception; Blazor Server tears down the circuit (or WebAssembly logs to the console) and shows the re…
android.os.NetworkOnMainThreadException
The app made a network call on the main (UI) thread, which Android forbids.
WindowManager$BadTokenException: Unable to add window -- token null is not valid; is your activity running?
A dialog or popup was shown with a context whose Activity is finishing/destroyed, or with the Application context.
Main Thread Checker: UI API called on a background thread: -[UIView setNeedsLayout]
UIKit was used from a background thread; UI must only be touched on the main thread.
AAPT: error: resource x (aka y) not found — Android resource linking failed
A layout, manifest or style references a resource (drawable, string, style, attribute) that doesn’t exist in the module or its de…
AAPT: error: resource android:attr/lStar not found
A dependency (androidx.core 1.7+) uses an attribute from Android 12 (API 31), but your module compiles against an older compileSd…
ANR: Application Not Responding (Input dispatching timed out)
The main thread was blocked for about 5 seconds (input) or a broadcast/service took too long, so Android showed “App isn’t respon…
Room: Cannot access database on the main thread since it may potentially lock the UI for a long period of time
A Room DAO query ran on the main thread; Room forbids it by default.
Two steps away (22)
System.NullReferenceException: Object reference not set to an instance of an object
Code dereferenced a variable that is `null` — the .NET equivalent of Java’s NullPointerException.
ObjectDisposedException: Cannot access a disposed context instance
Code used a DbContext after its scope ended — usually async void, fire-and-forget tasks, or capturing a scoped context in a singl…
HTTP Error 500.19 - Internal Server Error: The requested page cannot be accessed because the related configuration data for the page is invalid
IIS can’t read web.config — usually the ASP.NET Core Hosting Bundle (AspNetCoreModuleV2) or URL Rewrite module isn’t installed, o…
ECS task stopped: CannotPullContainerError: pull image manifest has been retried ... / ref pull has been retried
The ECS task couldn’t pull its image — no network route to the registry, missing ECR permissions, or a wrong image tag.
Error response from daemon: network X not found
The container or Compose project refers to a Docker network that doesn’t exist (any more).
Error response from daemon: Pool overlaps with other one on this address space
Docker tried to create a network whose subnet clashes with an existing Docker network (or a VPN/host route).
ActivityNotFoundException: Unable to find explicit activity class; have you declared this activity in your AndroidManifest.xml?
An Intent targets an Activity that isn’t declared in the manifest, or an implicit intent has no app to handle it.
IllegalStateException: Can not perform this action after onSaveInstanceState (fragment transaction)
A FragmentTransaction (or DialogFragment.show/navigation) ran after the Activity saved its state, typically from an async callbac…
IllegalStateException: Fragment x not attached to a context / not attached to an activity
Code called requireContext()/requireActivity()/getString() after the Fragment was detached — usually in an async callback.
HTTP 412 Precondition Failed
A conditional request header (If-Match, If-Unmodified-Since) didn’t match the current state of the resource.
HTTP 428 Precondition Required
The server requires a conditional request (If-Match / If-Unmodified-Since) to prevent lost updates, and you didn’t send one.
java.lang.InterruptedException (sleep interrupted)
A blocked thread (sleep, wait, join, queue take) was interrupted by another thread.
Gradle: Could not resolve all files for configuration / Could not resolve dependency
Gradle couldn’t download a dependency — wrong coordinates/version, missing repository, offline mode, or network/proxy issues.
Manifest merger failed: android:exported needs to be explicitly specified
Targeting Android 12 (API 31)+ requires `android:exported` on every activity, service or receiver that has an intent-filter.
Duplicate class X found in modules A and B
Two dependencies ship the same class — typically old Android Support libraries mixed with AndroidX, or Kotlin stdlib-jdk7/jdk8 ve…
Gradle: Unsupported class file major version / Android Gradle plugin requires Java 17 to run
The JDK running Gradle doesn’t match what the Gradle version or Android Gradle Plugin (AGP) supports.
Kubernetes: Pod stuck in Pending — FailedScheduling: 0/3 nodes are available
The scheduler can’t find a node that satisfies the pod’s resource requests, selectors, taints or volume constraints.
Kubernetes: Pod Evicted — The node was low on resource: memory / ephemeral-storage
The kubelet removed the pod because its node ran short of memory or disk.
HTTP 504 Gateway Timeout
A proxy or gateway waited too long for the upstream server to respond and gave up.
Cloudflare Error 524: A Timeout Occurred
Cloudflare connected to the origin, but the origin didn’t send an HTTP response within 100 seconds.
HTTP 304 Not Modified
The cached copy is still valid, so the server sends no body and the client reuses its cache.
Room cannot verify the data integrity. Looks like you've changed schema but forgot to update the version number
The Room entity definitions changed, but the database version wasn’t increased or no migration was provided.
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