Error Tracking troubleshooting

This page covers troubleshooting for Error Tracking. For setup, see the installation guides.

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Exceptions not appearing

If PostHog isn't capturing errors:

1. Use the SDK Doctor to verify your SDKs are updated to the latest version

2. Verify exception capture is enabled on the Configuration page in Error Tracking

3. Only unhandled exceptions auto-capture. For caught errors, use posthog.captureException():

   JavaScript

   PostHog AI

   try {
       // code that errors
   } catch (error) {
       posthog.captureException(error)
   }

4. Wait a few minutes and check Error Tracking in the PostHog app. Issues may take a few minutes to update after ingesting new error events

Source maps not resolving

If stack traces show minified code instead of original source:

1. Verify source maps are uploaded to the correct project by navigating to Error Tracking. You'll see warnings for missing symbol sets
2. Source map paths must match your production bundle URLs exactly
3. Upload source maps before deploying code that references them

See the source maps guide for upload instructions.

'Script error' with no stack trace

For security purposes, browsers hide error details from scripts loaded from different domains. This shows as Script error with no stack trace.

To fix, add crossorigin="anonymous" to your script tags:

<script src="https://your-cdn.com/app.js" crossorigin="anonymous"></script>

If the script is within your control, also set the Access-Control-Allow-Origin response header to your origin:

Access-Control-Allow-Origin: https://yourdomain.com

Or allow any origin:

Access-Control-Allow-Origin: *

You can also use session recordings to see what user actions triggered the error.

'Non-Error promise rejection' with no stack trace

This happens when you reject a promise with a string instead of an Error object. Without an Error object, there's no stack trace to capture.

new Promise((resolve, reject) => {
  reject('Something went wrong'); // String has no stack trace
});

Promise.reject('Something went wrong');

new Promise((resolve, reject) => {
  reject(new Error('Something went wrong')); // Error includes stack trace
});

Promise.reject(new Error('Something went wrong'));

For third-party libraries that reject with strings, wrap the rejection:

somePromise()
  .catch(err => {
    posthog.captureException(new Error(err))
    throw err
  })

'Minified React error' with no stack trace

In production builds, React removes debugging information to reduce bundle size. Errors look like:

Minified React error #123; visit https://reactjs.org/docs/error-decoder.html?invariant=123

To debug:

1. Upload source maps to get readable stack traces. See the source maps guide
2. Visit the error URL in the message to understand what went wrong
3. Watch session recordings to see what user actions triggered the error, then reproduce in development
4. Use a development build which includes full error messages. Only use this for debugging, not production

Symbol set upload skipped as already present

If the CLI reports Server returned 0 upload keys (1 skipped as already present), it means a symbol set with the same chunk ID already exists on the server. This happens when your bundle content hasn't changed between builds — the chunk ID is derived from the bundle's content hash, so identical code produces identical IDs.

To force a fresh upload:

1. Make a real change to your application code (not just a whitespace change), or
2. Delete the existing symbol set in the Error Tracking Symbol Sets UI and rerun the build

Grouping or assignment rules disabled

Rules can become disabled if PostHog encounters a processing error while evaluating the rule during exception ingestion. When a rule is disabled, a banner appears in the Error Tracking Configuration tab showing the error message.

To fix and re-enable a disabled rule:

1. Go to your custom grouping rules or auto assignment rules in the Configuration tab
2. Find the rule with the disabled banner and review the error message
3. Edit the rule to correct the configuration issue
4. Save the rule – this automatically re-enables it

If the error persists after editing, reach out to support.

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