Dear All
I run a small computer repair and services company in the UK. I can confirm that the Fall Creators Update will not let Classic Shell run.
I have now installed the Creators update on three different machines one of which is clean install of windows 10. In all three installing the latest classic shell either after the update or prior to it causes the following symptoms on first boot to desktop after it.
Windows logs on successfully but does as classic shell begins execution explorer fails and exits and tries to start again and as classic start menu loads fails and the cycle repeats.
I do not think this is a coincidence as MS has taken an aggressive stance on users installing alternatives to its built in Antivirus, Audio Player, Browser and Image Viewer etc. Updates either disable or damage AV and file associations are reset with the message that a an app default was reset. see the following post from
tenforumsdated May 2017 so this is not a new policy.