08-0400-00000000-515 error

Try the four steps in this thread:
http://forum.z8games.com/showthread.php?t=293087

The error you're getting is different from that one but I don't believe CF is using the 9020 version of Xtrap any more and you may have to force it to update to the latest version. I got the error listed in that thread and those steps worked for me.

As well the "tool name: mssbus.dll" suggests that "mssbus.dll" is a program on your computer that Xtrap is conflicting with. I'd recommend trying to figure out what that file is, I couldn't find anything on Google about it. Don't delete anything unless you know what it is and that it would be safe for your computer if you did so.

Also check your firewall program and ensure that all programs associated with CrossFire are allowed through it.