MyBB Community Forums

I am assisting another admin on fixing his website up.

I ran across this error. I was changing my Signature in my UserCP (/usercp.php?action=editsig) and as soon as I clicked on the Update Signature button...

I got this error as shown below.

I do recall a while ago that someone had a similar issue, but I can't remember what the solution to this issue was.

Can someone help me out?

Bump!

I still need assistance with this issue.

Can anyone help?

This is most likely caused by Apache's mod_security. The straightforward solution is to disable it, either you or your hosting provider.