I have about 50 computers to upgrade to office 365 office 2016 business premium. I have upgraded 10 computers. The previous office installs were 7x2010 and 3x2013. The installs went fine for the previous 2013 offices. The previous 2010 offices had issues once the 2010 office was uninstalled. A repair of the office 2016 installation fixed some of the issues. The issues were office documents opened were blank.
2 computer still have issues with access. We use a runtime front end version of an access DB .accdr. The db will open in accdb but when it is changed to a accdr it gives and error.

Microsoft access cannot open this file.
This file converted to runtime mode by changing its file name extension to .accdr. This file will open only when access is in runtime mode.To open the file double click it in windows explorer, open it by using a shortcut, or use the /runtime command line switch. to modify the design of this database, rename it with an .accdb file name extension and open it in access

I have repaired
reinstalled
associated file
default program to open id access
Called Microsoft but it is out of their scope, client usability.

I should have uninstalled 2010 then installed 2016.

Any help would be appreciated


Thanks