Cloudflare Workers Error 1101 and 1102

How to fix it

Try these in order — the most common fix is first.

1. 1. Find the exception

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   1. Run npx wrangler tail
   2. Enable Workers Logs and filter on $workers.outcome = exception
   3. Enable source maps for readable stack traces
   Did this fix it? Yes No

2. 2. Fix never-settling responses

   1. Ensure every promise resolves or rejects and close server-side WebSockets
   Did this fix it? Yes No

3. 3. Reduce CPU time (1102)

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   1. Check Worker Errors > Exceeded CPU Time Limits in Workers Metrics
   2. Move heavy work out of the request path
   Did this fix it? Yes No

4. 4. Related errors

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   1. 1019: a Worker called itself over 16 times, remove the recursion
   2. 1042: use a service binding or the global_fetch_strictly_public flag
   Did this fix it? Yes No

Symptoms

The Worker URL shows 'Error 1101 Worker threw exception' or 'Error 1102 Worker exceeded resource limits'.

Why it happens

• Uncaught exception in the Worker
• Promise never resolves or WebSocket never closed
• CPU time limit exceeded
• Related: 1019 loop limit, 1042 same-zone fetch

This guide also covers

• cloudflare worker error 1101
• cloudflare workers error 1102
• worker threw exception

Other Cloudflare errors

• Cloudflare Error 521: Web Server Is Down
• Cloudflare Error 522: Connection Timed Out
• Cloudflare Error 524: A Timeout Occurred
• Cloudflare Error 525: SSL Handshake Failed
• Cloudflare Error 526: Invalid SSL Certificate
• Cloudflare Error 520: Web Server Returned an Unknown Error
• Cloudflare Error 1020: Access Denied
• Cloudflare Error 1015: You Are Being Rate Limited