Can't access my files after upgrade from 18 -> 19 and 19 -> 20 - Need Help

Hi:
I am in a jam. I have tried everything for 3 days to make nextcloud work with no luck.
I get a message when I click on Files “This operation is forbidden”
I have looked everywhere and there is not much on the internet about this problem.
Is there anyone out there who can help? I’m not sure how this works but maybe you can make me an offer?
Thanks in advance for anyone who can help.
Joe