When searching for knowledge-base articles, some or all KB articles that should return are not being found. This happens on both the Knowledge Base and Home tabs of the Process Manager portal.
This knowledge-base article will show you how to recreate the Lucene indexes that are used when searching the KB in your ServiceDesk system.
This will take a considerable amount of time to run if you have a high volume of KB articles. It is recommended to do this after business hours. Once the CreateIndex operation is completed, you will be able to search your Knowledgebase.
This will always happen in a load balanced environment, but other circumstances can cause problems on environments running on a single server.