ArcSight search never completes

I am observing an issue from our ArcSight console when doing any basic search.  From the Analyze > Search page, when you enter a search string and click GO, the search never completes.  The number of scanned events eventually stops incrementing, but the search appears to keep going and never actually stops to indicate it has completed.  You have to manually click the Cancel button every time. This just started happening recently.

We are running HPE ArcSight Logger: 6.3.1.7874.0.  Are there any general issues which can cause this, and what would be a good option to try and fix this?  Unfortunately I don't know a whole lot about this product, and was hoping to find some common things to check/try.

Jim