
This problem has been reported by a number of other users. Microsoft is aware of the problem and will no doubt push an update to correct it shortly. Meanwhile, here is a method that reportedly solves the problem (courtesy of og_tech by way of Sumit - Insider MVP):
- Right-click Start>Run.
- Type regedit and press Enter.
- Go to:Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options
- Delete the folders of the apps that do not work and check.
If you are reluctant to edit the Registry, the only alternative at the moment is to use Word Online.
There's also an indication that Avast is implicated; Microsoft Agent Gabriel Bratton has posted: "If you use Avast, make sure it gets updated. This appears to be an issue caused by Avast, https://forum.avast.com/index.php?topic=233129.msg1541192#msg1541192. The thread says they are working on a fix."