When doing a word search, usually the search results display under Context Hits.  I can click on any of the hits and the searched criteria displays and is highlighted. 

However, sometimes I get a message of how many hits there are and a message of "Hits not shown" and I can't view the hits.  Even when I open one of the documents in the search results list, it still will not take me to or highlight the searched criteria.  Why not?

I've attached screen prints of an example of when hits are displayed and when they are not.