Hi Terry,

Welcome to the Box Community!

Have you tried to manually reset you Box Drive app to see if this help fix the issue after your upgrade? If not, could you try this and follow the steps in this article: Manually Resetting Box Drive 

If you've already done this and still having issues, please go ahead and submit a ticket to Product Support on this page to help you further troubleshoot this issue.

Thanks for your participation in the forum and let us know how else we can help!

I regularly experience the same thing, Box stops syncing, sometimes the app completely disappears or stops working, and uploading and downloading fails causing missing or corrupted files.