You just applied the latest Portal+WCM fixpack and cannot crawl the JCR search collection "JCRCollection1" as defined in the information center link here:
Resolving the problem
1) Uncheck the forceCompleteCrawl check box from the manage search >> search collection >> JCRCollection1 >> JCRSource content source settings.
- Selecting a force full crawl will always discard the received documents and cause a fullcrawl request.
2) Using the native SQL interface that is available for the DB you are using with Portal, execute the queries listed below. These will reset the crawler and free the resources.
i) Delete from jcr.icmstjcrtsseedlistpending
ii) Delete from jcr.icmstjcrtssubscriptionmanager
iii) Update jcr.icmstjcrtsfullcrawltopics set subscriberid=null,ts=null
3) Enable trace com.ibm.icm.ts.*=finest. Please provide the complete crawling trace files.
4) Run the crawler twice with an interval of 10 minutes in between.(during first run it always returns 0 documents as for first request it would trigger an fullcrawl inside jcr and in the next request updates are sent).
5) In case if you find that crawler does not receive the documents, please open a ticket with support and upload the trace logs.