We have an old version of QuickBooks, Pro Desktop 2015. We had the same problem with it after upgrading to Office 365. We took the opportunity to upgrade the PC to Window 10 from 8.1 to try to fix the problem. The upgrade to Windows 10, removing all apps and personal files, and then installing Office 365 and then QuickBooks failed to fix the problem. A new install of Windows 10 on the bare metal, then installing Office 365 and then QuickBooks failed to fix the problem.
A new install of Windows 10 on the bare metal, then installing QuickBooks and then Office 365 FIXED the problem. In my case, the key was to install QuickBooks before installing Office 365. This solution preserves x64 OS and Office 365.
I don't know if upgrading to Windows 10, removing apps and personal files, and then installing QuickBooks, then Office 365 would have fixed the problem. I didn't try it.
