After upgrading to the latest 7 Days client I upgraded the dedicated server via the RAT 4 client then tried to join. It didn't work and received these errors:
2023-08-11T22:14:54 128.031 INF [Auth] PlayerName authorization successful: EntityID=-1, PltfmId='Steam_76561197983177251', CrossId='EOS_0002a05e472447b59b0078fb759bbcbc', OwnerID='<unknown/none>', PlayerName='natenaterollerskate', ClientNumber='1'
2023-08-11T22:14:33 106.403 ERR [Web] Error in Web.ctor:
2023-08-11T22:14:33 106.415 EXC Only one usage of each socket address (protocol/network address/port) is normally permitted.
2023-08-11T22:14:55 128.534 ERR [EOS] Failed unregistering player in session: NoChange
2023-08-11T22:14:55 128.555 ERR DisconnectClient: Player EOS_0002a05e472447b59b0078fb759bbcbc not found
Then, I decided to try upgrading the dedicated server via Steam directly and that seemed to work better. I restored a database backup via RAT (glad to see that's working great in v4 already!). This fixed it right up. So perhapse the database upgrade via RAT4 isn't quite there yet, no biggie, easy workaround.
2023-08-11T22:14:54 128.031 INF [Auth] PlayerName authorization successful: EntityID=-1, PltfmId='Steam_76561197983177251', CrossId='EOS_0002a05e472447b59b0078fb759bbcbc', OwnerID='<unknown/none>', PlayerName='natenaterollerskate', ClientNumber='1'
2023-08-11T22:14:33 106.403 ERR [Web] Error in Web.ctor:
2023-08-11T22:14:33 106.415 EXC Only one usage of each socket address (protocol/network address/port) is normally permitted.
2023-08-11T22:14:55 128.534 ERR [EOS] Failed unregistering player in session: NoChange
2023-08-11T22:14:55 128.555 ERR DisconnectClient: Player EOS_0002a05e472447b59b0078fb759bbcbc not found
Then, I decided to try upgrading the dedicated server via Steam directly and that seemed to work better. I restored a database backup via RAT (glad to see that's working great in v4 already!). This fixed it right up. So perhapse the database upgrade via RAT4 isn't quite there yet, no biggie, easy workaround.