Tx for trying thee lucene plugin. There are a few things to check first:
0) you need to run the script from the command-line (means you need a php-cli version as for the other php scripts provided with ez publish), not through the web browser
1) Is the extension activated (the checkbox should be checked) in the admin interface
2) Verify that the php-java bridge is running: first look if java is listed as a PHP extension in admin->setup->system information, and then see if a Java process is started (there is a test php script supplied with the php-java bridge which shows even more). I'll add some checks on this in the scripts so we get meaningful debug output 3) is the directory writable by the Apache process?
