Luke comes with a released version of Lucene probably, while solr is using a later version. You have to start luke with the solr Lucene jar on the classpath. There are directions to do this type of thing on the Luke webpage.The main thing that bugs me about this index now is that the latest version of Luke (0.8.1) won't open it. ("Unknown format version: -6") The Solr Luke handler works fine with it, though.
- Mark