A 406 on cPanel/LiteSpeed servers is almost always a ModSecurity rule blocking your request — typically when a form, post, or URL contains content the firewall flags as suspicious.
- Note exactly what you were doing — submitting a form, saving a post, or uploading. The triggering content (certain code, symbols, or keywords) is the clue.
- Check cPanel ModSecurity (if available) to see the recent hits and rule IDs.
- Try the action with simpler content to confirm a specific phrase is being blocked.
- If it is a false positive on your own legitimate content, we can whitelist the rule.
Open a ticket with the exact URL, the time, and the rule ID if you can see it, and we will adjust ModSecurity.
