On my localhost using Xampp I cannot revert any templates. The error messages are not always the same either. This is a my install that I do all of my styles on so I currently have 19 styles plus the default style. Here are 2 of the error message I receive.
Fatal error: Maximum execution time of 60 seconds exceeded in C:\xampp\htdocs\xf\community\library\Zend\Db\Statement\Mysqli.php on line 70
Fatal error: Maximum execution time of 60 seconds exceeded in C:\xampp\htdocs\xf\community\library\Xenforo\Template\Compiler.php on line 597