OS 5 broke Mac (OSx) connections

After upgrading from OS 3 to 5.05.111, 2 of 3 Macs (so far) are unable to connect. Any idea why I get “You do not have permission to access this server.” It is unclear to me why 1 is working. I have tried:

This fixed 1 of my Macs, but didn’t work on 3 others. 1 magically started working. So frustrated.

Problem solved: In My Cloud OS, turned off Network / Windows Services / Active Directory. Thankfully, it isn’t mission critical.