| 413 Request Entity Too Large | Nginx Error Code 413: How to Fix It | medium | Easy |
| 499 Client Closed Request | Nginx Error Code 499: How to Fix Client Closed Request | low | Medium |
| 502 Bad Gateway - upstream prematurely closed connection | Nginx Error Code 502 Bad Gateway: How to Fix It | high | Medium |
| 504 Gateway Timeout | Nginx Error Code 504 Gateway Timeout: How to Fix It | high | Medium |
| SSL_do_handshake() failed | Nginx SSL_do_handshake() Failed: How to Fix It | medium | Medium |
| no live upstreams while connecting to upstream | Nginx No Live Upstreams While Connecting to Upstream: How to Fix It | critical | Medium |
| upstream timed out (110: Connection timed out) | Nginx Error Code Upstream Timed Out (110): How to Fix It | high | Medium |
| worker_connections are not enough | Nginx Server Worker Connections Error: How to Fix It | high | Medium |