Site crashes on language change from Serbian to English

Hi,

I have been configuring a Zen Cart shop on a test domain for quite some time now.

I have a multilingual site, the main language is set to Serbian.

The problem is - when you switch from Serbian to English, the page is blank and the site doesn't load at all until you clear your cookies and the language changes back to Serbian.

Now I haven't switched to English in a while and have done a lot of changes recently, and I don't have a clue what could be causing the problem. No errors at all, just a blank page. I tried the debug error-logging tool but there is no error log in the cache folder.

Is there a way to find out why it is broken? I hate to return the couple-of-days old backup because of this :/

The address is: http://micko.lolmao.info/

Running Zen Cart 1.3.8a.

Thanks in advance.

Well, I couldn't wait any longer and decided to restore the backup. I was being stuck on this for too long.