Crystal Report running fine but now crashes with "not responding" when refreshed

Crystal reports 11.5 - am running a report that has always worked just fine that I run once a month. When I ran it this month, I get "not responding" when I refresh the report. The connection hasn't changed and I can Verify database is up to date. I'm also told that nothing has changed with the database/tables. I also tried to create a new report, created a connection and when I tried to pull data from the tables, it crashed again with not responding. My other crystal reports that I use with other servers are run just fine as well. Just this one database. Where to look?