I can now confirm that AppNap was definitely the culprit. I was contemplating going back to Office 2011 because of this issue. My wife is a freelance editor and teaches writing so it was bugging her, too.mikehalloran wrote:I have an issue with Word 2008 in Sierra being unresponsive if it's been open too long. App Nap might be the culprit. ...
This wasn't an issue in El Cap for some reason. Office 2008 cannot be installed in Sierra but, like DP 7.24, it still works if installed in a previous OS. 2008 got really slow in OS 10.8 and I went to 2011 for a few years but never liked it. In Yosemite, it became snappy again and even better in El Capitán ... no idea why and we're not complaining over here.
Thanks for this thread!