Back to Demos
31/52
TroubleshootingIntermediate
Let's Encrypt Troubleshooting
Troubleshoot common Let's Encrypt and Certbot errors. Fix HTTP-01 and DNS-01 challenge failures.
Interactive Demo
Top 5 Errors - Quick Fixes
| Error Message | One-Line Fix |
|---|---|
| too many certificates already issued | Wait 7 days or use different subdomain |
| Challenge failed for domain | Check port 80 open, DNS points to server |
| Connection refused | Firewall blocking port 80/443 |
| DNS problem: NXDOMAIN | Domain doesn't resolve to your server |
| Timeout during connect | Server unreachable from internet |
Most Common Cause
90% of Let's Encrypt failures are: port 80 blocked, DNS misconfigured, or rate limited.