Issue: Your crawl component stops responding and the content source is is stuck on a crawling, starting, or stopping status. You may try a multitude of solutions and eventually attempt to delete and recreate the service application. Upon creation of the search service application and opening it you are greeted by this message.
Resolution: This error is a fun one, and by fun I mean painful. I researched a lot of various solutions but the most consistent answer was as follows. Please note that this is not a guaranteed resolution, but a common one:
- Delete your search applications
- Run the Farm Configuration Wizard to create a search service application
- Rec-create your search service applications as needed
- Note: you may receive the same error when initially created. Give it a few minutes.