I cannot save some settings in my vBulletin

[Dan@TT]

First of all, Hello

I'm having some issues with my vBulletin 3.6.4 that I bought yesterday. I have installed it to my server, everything is ok , database communication works, anyways it's up, if I am permited to post the url: www.travel-talk.info

Anways, I've started to customize the forum from my admin cp but some problems started to show up:

in vBulletin Options I can't save every setting that I modify. I got a blank screen after (see in my attached picture) , and also , in Forum Manger , I cannot edit my Categories, Forums and I cannot add any other forums. I got the same blue screen.

What's wrong with it?

Thanks

Here's the blue screen after I try to save.



Any advice is appreciated !