Hello, In an other mail, I talked about a problem compiling lucene plugin. I had many "Unknown symbol"... Apparently maven couldn't find its classes in org.apache.lucene/lucene- core-2.4.1.jar I have discovered that lucene plugin depends on xwiki-core which has some dependency on JackRabbit which seems to pull a dependency on lucene/lucene version 1.4.3 which contains also some of the classes of org.apache.lucene /lucene-core-2.4.1.jar but older versions... After trying many things, I've modified the lucene plugin pom.xml by inverting dependency to xwiki-core and lucene-core so that lucene-core is the first to be loaded and it solves my problem... Apparently, you don't have the same problem as me when building so I think it is linked to my local environment but anyway the inherited dependency on 2 versions of Lucene might be problematic some time. br Pascal