Scrivener crashes with "select all"

I’m using Windows 7 and have been using Scrivener since last fall. I tried “select all,” in order to change the text size in various scenes. Each time Scrivener goes into the “Scrivener not responding” mode. Then it crashes. I’ve restarted the computer several times and no change. This happened several months ago and I think when I restarted the computer things worked OK. Not sure though. However I was doing some “select all” yesterday and things worked fine. FYI