In progressRequests fail with Error 1101Cloudflare returns Error 1101 whenever a Worker's own JavaScript throws an uncaught exception. The 1101 page itself never says what threw — the real cause is always in your own logs.
View the whole map (7 more steps)
Find the actual exception behind the 1101
Fix the specific exception
Check for the "script will never generate a response" variant
Ensure every code path resolves a Response
Not resolved by inspecting your own code — escalate
Redeploy and repeat the failing request
Resolved
What to test
Requests fail with Error 1101
Cloudflare returns Error 1101 whenever a Worker's own JavaScript throws an uncaught exception. The 1101 page itself never says what threw — the real cause is always in your own logs.