Error category
Fix Cloudflare DNS, SSL, WAF, Workers, Pages, and origin connectivity errors that block deployments or make proxied applications fail.
This Cloudflare troubleshooting hub collects real error signatures, quick fixes, common causes, and step-by-step debugging paths for developers who need a practical answer instead of a broad overview.
76 crawlable articles in this category. 51 additional records are indexed in JSON only (no standalone HTML route).
Browse Cloudflare records in the data catalog — search JSON index entries, including data-only records without standalone HTML guides.
Start by matching the exact error message, then check the technology, environment, credentials, network path, and deployment context. The pages below are grouped so you can move from broad Cloudflare symptoms to specific root-cause families without relying on client-side search.
Evidence labels are derived at build time from each Markdown record. Source-backed entries have public URLs under a Sources checked section, while partial-source entries expose public links without a complete source block.
These entries include public source URLs in the imported page body. Use them first when you need evidence for provider behavior, SDK regressions, or version-specific failures.
Web developers whose sites are protected by Cloudflare experience intermittent 522 errors preventing visitors from reaching their origin servers; need diagnostic steps and resolution methods Includes evidence for Cloudflare troubleshooting demand.
Error 522 Origin connection timed out — Cloudflare Workers unable to reach upstream origin Diagnose and fix Cloudflare 520 error when origin server returns garbled or empty response after TCP connection succeeds, distinguishing from 522 timeout and 524 gateway timeout Includes evidence for Cloudflare troubleshooting demand.
"Error 520: web server returns an unknown error" — connection established but response is empty/malformed/reset Fix Cloudflare 524 timeout errors by identifying slow backend processes and optimizing origin server response times within the 120-second proxy read timeout window Includes evidence for Cloudflare troubleshooting demand.
524 A Timeout Occurred — TCP connection succeeded but origin did not respond within 120-second proxy read timeout Diagnose and fix Cloudflare 522 errors where origin server doesn't respond to TCP handshake — caused by server overload, firewall blocking Cloudflare IPs, KeepAlive disabled, or DNS misconfiguration Includes evidence for Cloudflare troubleshooting demand.
Error 522: connection timed out — Cloudflare times out contacting the origin web server within ~15 seconds, TCP handshake never establishes Site owner sees Cloudflare Error 522 and needs to diagnose whether it's caused by server overload, firewall blocking CF IPs, incorrect DNS/A record, or network issues — then implement fixes. Includes evidence for Cloudflare troubleshooting demand.
522 Connection Timed Out — Failed TCP handshakes between Cloudflare and the origin server. The origin did not return a SYN-ACK within the timeout window (15 seconds). Fix deployment failures where Cloudflare Workers SDK returns 502 during asset upload phase Includes evidence for Cloudflare troubleshooting demand.
502 Bad Gateway during Differential Uploads POST /pages/assets/upload Developer building Cloudflare Worker with Python runtime hits silent upload failure when sending files above 1MB via multipart/form-data; no documentation warning about this limit exists. Includes evidence for Cloudflare troubleshooting demand.
Python Workers: multipart/form-data body parsing fails at ~1 MB (undocumented limit). Upload file <=1024 KB succeeds, >=1040 KB fails before reaching application code. Developer deploying Workers via Wrangler discovers unexpected custom domain ownership changes when deploying to different environments due to routes inheritance bug Includes evidence for Cloudflare troubleshooting demand.
[bug] routes inheritance silently transfers ownership of custom domains between env Workers on every deploy (Wrangler 4.x) Debug Cloudflare Wrangler CLI login command hanging when OAuth callback returns an error (not access_denied), waiting full 120s timeout instead of surfacing the actual OAuth error to the user Includes evidence for Cloudflare Workers troubleshooting demand.
wrangler login hangs until 120s OAuth timeout — OAuth provider redirect with error code not shown to user Fix Cloudflare Wrangler deployment crash on headless Linux when browser-based OAuth login fails due to missing xdg-open binary Includes evidence for Cloudflare Workers troubleshooting demand.
[ERROR] A file or directory could not be found. Missing file or directory: xdg-open Fix unclear error messages when deploying SolidStart/Vinxi apps to Cloudflare Workers — errors don't mention module scope restriction which is the actual cause of build/deploy failure Includes evidence for Cloudflare troubleshooting demand.
Cloudflare Workers deployment fails with unhelpful errors for setInterval at module scope, Database Pool creation at module scope, Auth instance at module scope Understand why Cloudflare Response Header Transform Rules don't apply to WAF challenge block responses, breaking cross-origin JavaScript fetch() calls Includes evidence for Cloudflare troubleshooting demand.
WAF challenge 403 response lacks Access-Control-Allow-Origin CORS headers despite Response Header Transform Rule configured — cross-origin fetch() calls fail Fix Cloudflare Pages Functions returning 1101 error on all URLs when using [[name]].ts catchall route files (wrangler 4.77+) Includes evidence for Cloudflare troubleshooting demand.
TypeError: Missing parameter name at index 11: /:catchall* → Cloudflare Error 1101 Worker threw exception Identify what Cloudflare services are currently experiencing outages or degradation so affected sites can diagnose root cause and implement mitigation Includes evidence for Cloudflare troubleshooting demand.
Minor Service Outage — Cloudflare page indicator shows 'minor' severity (updated 2026-05-22T18:52:06.999Z) Fix Cloudflare Go SDK DNS deserialization bug where MX records lose their priority field because union type discriminator incorrectly picks ARecord type Includes evidence for Cloudflare troubleshooting demand.
cloudflare-go union type discriminator resolves MX records as RecordResponseARecord instead of RecordResponseMXRecord; r.Priority always returns 0 for MX records despite API returning correct value Fix Cloudflare 522 errors caused by origin server hanging behind Workers proxy Includes evidence for Cloudflare troubleshooting demand.
Cloudflare Error 522: Origin server connection timeout — worker script executed but origin returned no data within 100s Troubleshoot and fix Cloudflare 520 error caused by origin server crashes, header size limits, firewall blocking, or short idle timeouts Includes evidence for Cloudflare troubleshooting demand.
Error 520: Web Server Is Returning an Unknown Error Developer deploying Next.js on Vercel behind Cloudflare finds proxy.ts middleware silently skipped in production, breaking API proxy and security header functionality Includes evidence for Cloudflare troubleshooting demand.
proxy.ts does not execute in production when behind Cloudflare Proxy; middleware.ts works but proxy.ts bypassed entirely when Cloudflare is in the path Resolve wrangler secret put failure when input contains non-ASCII characters (Unicode > 255) Includes evidence for Cloudflare troubleshooting demand.
[ERROR] Cannot convert argument to a ByteString because the character at index 7 has a value of 8230 which is greater than 255 Developers using Cloudflare Go SDK cannot detect URL scan errors because the API returns an 'errors' array that the SDK model omits, causing silent infinite retry loops in production. Includes evidence for Cloudflare troubleshooting demand.
errors node available via API not exposed to SDK; task.success check leads to infinite retries when scanning returns errors instead of success/failure Continue through the full static archive for this hub. Every listed page is crawlable and keeps its existing canonical URL.