How to Fix Nginx Fatal Error on Ubuntu 22.04

The Root Cause A “Nginx Fatal Error” on Ubuntu 22.04 primarily stems from critical syntax errors within its configuration files, preventing the Nginx daemon from parsing directives and successfully starting. This often occurs following manual edits to nginx.conf or site-specific configuration files, introducing malformed commands or missing required characters like semicolons.

Quick Fix (CLI) The immediate step is to pinpoint the exact configuration error blocking Nginx from starting. This command will validate all Nginx configuration files and report any syntax issues, including the file path and line number of the error.

sudo nginx -t

If nginx -t reports “syntax is ok” but Nginx is not running, attempt a clean restart:

sudo systemctl restart nginx

Configuration Check Based on the output from sudo nginx -t, identify the problematic configuration file and line number. Common files include /etc/nginx/nginx.conf, files within /etc/nginx/sites-available/ (symlinked to /etc/nginx/sites-enabled/), or files in /etc/nginx/conf.d/.

Using a text editor, open the identified file (e.g., sudo nano /etc/nginx/sites-available/default) and correct the syntax error. Typical fixes involve:

• Adding a missing semicolon (;) at the end of a directive.
• Correcting misspelled directives (e.g., serverr_name to server_name).
• Ensuring proper matching of curly braces ({}) for blocks.
• Correcting paths or file permissions for included files or log files.

Verification After making changes, verify the Nginx configuration syntax again, then restart Nginx and check its service status.

sudo nginx -t
sudo systemctl restart nginx
sudo systemctl status nginx