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MtrXTools

Error explainer

Paste an error from a browser, curl, your code (Python, Java, Go, .NET, Node.js), git, SSH, Docker, nginx, a CDN or an email bounce, and see what it means, the usual causes and how to fix it, with the MtrXTools tool that confirms it opened on the host named in the message. Matching runs in your browser.

Paste the error, get the fix

Paste an error message or a whole log line. MtrXTools recognises it, explains what it means in plain terms, lists the usual causes and fixes, and opens the tool that confirms the cause, already filled in with the host named in the message.

Over 250 errors are covered: browser certificate and connection errors such as NET::ERR_CERT_DATE_INVALID, curl, OpenSSL and Node.js errors, Python, Java, Go, .NET, PHP and Ruby exceptions, git, SSH, npm, Docker and kubectl failures, DNS and socket errors, HTTP status codes and Cloudflare, CloudFront, Vercel and Heroku error pages, nginx, Apache and Let's Encrypt errors, and email bounces from Gmail, Microsoft 365 and Yahoo such as 550 5.7.26.

Questions

Is what I paste sent anywhere?
No. Matching happens in your browser. Only short pastes are kept in the page URL, so you can share them.
My error isn't recognised. What now?
Paste the exact code or the full line rather than a summary. The list of known errors on this page links to a full page for each one.
Which errors does it know?
The full list is below, grouped into browser and TLS, command line, languages and runtimes, dev tools and SSH, network, DNS, HTTP and CDN, web servers and certificates, and email. Type in the filter to search it, for example 5.7.1, PKIX or 1020.

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