We have a long outstanding bug that affects the search. Apparently there are indexed items that have long been deleted. Or the indexing is wrong in some way (which is more likely, because almost nothing gets ever deleted):

22:00:34,766 DEBUG [ObjectLoader] Object found in Search index but not in database: class org.jboss.seam.wiki.core.model.WikiDocument wih id 11139
22:00:34,769 DEBUG [ObjectLoader] Object found in Search index but not in database: class org.jboss.seam.wiki.core.model.WikiDocument wih id 11219
22:00:34,771 DEBUG [ObjectLoader] Object found in Search index but not in database: class org.jboss.seam.wiki.core.model.WikiDocument wih id 11224

It's hard to tell what the "Object" was because I can't see any useful data about it in the index.

This is unlikely to be resolved soon, I wouldn't even know where to start looking. It's all fixed by rebuilding the search index in the admin screen manually from time to time. So if someone complains about the search results, rebuild the index.