After the upgrade from Beta 6 to Beta 7 I am not able to connect to any smb-shares any more. I tried it with a Windows Server, Synology DriveStation and a Debian implementation. I'm directly getting the message Error with connection.
Did this on both machines and it's working again. Thanks to TyngJJ
Unredacting the logs reveals the issue, insufficient permissions to load the kernel extension. Just run this (once):
sudo kextload /System/Library/Extensions/smbfs.kext
Edit: filed as FB8628919