I use the software on multiple computers. One of them is still running windows 7 so l cant update cryptomator to the current version. I have though upgraded another system that uses windows 10. when I access the cloud based back up on the windows 10 computer l am getting a message that l need to upgrade my vault. If l allow the change to the vault will l still have access to those files when l try to access them from the windows 7 computer?
Only if you update Cryptomator on that win 7 computer, too.
Why not? While we stopped supporting Windows 7, we are not aware of technical problems using it anyway.