Thanks @Paul. Can I "un-use" the Windows User Account? Or am I now stuck with it?
I have been able to open the current database file. I had to check all 3 boxes in the database password dialog.
I've been able to open an old version of the database file after copying the key file to a new directory which is not backed up by OneDrive. But I still can't open the current version of the database.
I migrated my Windows PC to OneDrive this morning and lost the ability to open my password database. The database and the key file were both migrated. I tried opening KeePass without a database. Then tried File->Open->Open File specifying the location of my password database in my OneDrive location. When the Open Database dialog appeared, I checked the Master Password and Key file / provider boxes and supplied my password database password and the location of the moved key file. See first attachment....