If you are having trouble or issues with ZOO, this can have numerous causes. ZOO has a build in system check, to detect some of the problems. But there are some common issues that might arise:

Faulty Interface Actions - Javascript Errors

If you are having trouble with functions in ZOO, this might be due to a jQuery conflict. Please read javascript errors chapter on how to detect and resolve the problem.

Unstyled Content - No CSS Being Loaded

This might be due to file permission issues. Please read file permission issues chapter on how to detect and resolve the problem.

Blank Page

This is most likely due to a php error being thrown. Please enable the display_errors parameter in your php.ini. Only with an error message the problem can be found.

Another way to check for PHP errors, is to have a look at your PHP error log. The PHP log shows information on errors and warnings thrown by PHP. Your host should have configured PHP to write that information to a log rather than output them on screen.

Please check this guide to PHP error messages for webdesigners for a more thorough view on the subject.