I just installed the latest viewer version on a Mac running 10.15.6. I have a host installed on a Win 10 machine. In the viewer, 'update required' was showing Yes. I therefore upgraded from the 6.10.10 version to the beta 6.12.2b2, but it still shows 'Upgrade required'.
I also lost connection during the update, and had to complete it manually on the remote machine.