Using Sitecore 8.2 Update 4, Sitecore Experience Profile is not loading (the spinner keeps on spinning) on our Staging server using a Lucene index. This was working fine last week and i guess, it appears to be an intermittent issue.

I've checked the Log and Crawling log - no entries

Memory useage - 73%

CPU useage - increases to ~50% and holds steady

SQL Profiler isn't showing a massive load: Mainly calls to the EventQueue table

I can search for individuals by name or email in the Experience Profile, and that is quick. Any suggestions on how to diagnose this, would be highly appreciated.

I have rebuilt the Analytics index using AnalyticsIndexBuilder tool but this had no effect.

Let me know, if more information is required.