XF 1.2 Getting Error Suddenly

I just tried to access my website today, only to find a lovely error preventing me from doing so. I get the following error when I try to access my site:

Warning: require(/home/mineuniv/public_html/library/XenForo/Autoloader.php) [function.require]: failed to open stream: No such file or directory in /home/mineuniv/public_html/index.php on line 6

Fatal error: require() [function.require]: Failed opening required '/home/mineuniv/public_html/library/XenForo/Autoloader.php' (include_path='.:/usr/lib/php:/usr/local/lib/php') in /home/mineuniv/public_html/index.phpon line 6

The strange thing is, my site was working fine one day, then the next it was down, and I haven't change anything on the site (I didn't even connect through ftp to the site). THe strange thing is, now when I look in the /home/mineuniv/public_html directory, there is no 'library' folder. I was wondering if the site just somehow deleted it, or if there is anyway to restore this missing file. Any help would be appreciated.

Nvm, problem was solved, I found the 'library' folder located inside of the internal_data folder, I guess somehow it got moved, or maybe I moved it earlier and it just hadnt had this error until now.