XF 1.5 "Bad Request" when sending a PM


Active member
At random times i get the error in chrome:
Bad Request
Your browser sent a request that this server could not understand.

Apache/2.2.15 (CentOS) Server at www.cupcakethunder.eu Port 80

When i try to send someone a PM. Website replies/new threads etc seem to work fine.
When i then try on mobile it works.


XenForo developer
Staff member
This would generally mean the request isn't even reaching XF. There may be more details in your web server error log. You may need to bring your host to help identify the trigger. It may be a false positive with a security tool.