I ran into the exact same error as plevy.
It’s being caused by the file LowerCaseUtf8.php. Line 46 tries to require_once ‘Zend/Search/Lucene/Exception.php’, but fails. Probably because the include path isn’t set correctly.
That exception is only encountered if the server does not have mb_strtolower() support. The best solution is to configure PHP to support mb_strings, by compiling with –enable-mbstring or another method.
