I found this message in error.log
|xer_default_products||DocumentIndexer||E||Could not obtain Lock on lucene index Lock held by this virtual machine: C:\projectASF-Mars\ofbiz\runtime\indexes\products\write.lock|
Here is Jacopo's answer:
We should not worry (because the "lucene" component is just an experimental one) but let's keep an eye on it: it is caused when two threads are trying to update documents in the Lucene index; it may happen when two events modify data that trigger the execution of the document update. We could consider to enhance the DocumentIndexer to properly manage these scenarios.