Fatal Error translation..?
 

Can someone tell me what this means..?
I get it from clicking on a members name.

a function called GetActivityAll is not defined anywhere in the file member.php
Reupload member.php and overwrite the copy on the server, see if the problem has gone away. If not, then you will need to disable your plugins.

I know what mod i added to make this happen, but disabling "vBExperience" wont help me use it. :)
The mod works on many other sites, so im sure there is a fix. I just dont know where to start.. (already tried in the mod thread, & they tried, but it is not supported)

All you can do is just overwrite the copy of member.php on the server to remove GetActivityAll() from it.

If your problem is with a modification then you really should post about it in the thread of that modification. Even if marked unsupported, then that is still the place where you will find other members using the same product who might be able to assist you.