Can you post a picture of what you're getting (that save as dialog)?

Temporary solution would be to first create a file (via new... in context menu, or copy file and rename it) and then saving it normally when edited.

We will find solution in time ...

Checked known issues about 1809 Windows upgrade..


Do you have any of this installed?

Could be you turned on protected folders? Add office to allowed apps...

:arrow: Add or Remove Allowed Apps for Controlled Folder Access in Windows 10