I read on http://www.classicshell.net/forum/viewtopic.php?f=4&t=8147 (mirror):
I have decided to stop the development of Classic Shell. […] 2) Windows 10 is being updated way too frequently (twice a year) and each new version changes something that breaks Classic Shell.
Which Windows 10 versions work with Classic Shell?
Given that the forum post you linked was dated "Dec 03, 2017" I would guess Classic Shell is compatible with at least version 1709 as it was released in 2017 in the 9th month.
I was unable to correctly boot my Windows 10 version 1709 Build 16299248 yesterday. I was able to get to the login mask, but the desktop never loaded, leaving my screen black with a little white cursor which I could still move. This problem is not unusual I discovered after googling, but despite all the fixes suggested, ranging from "uninstall your graphics card" to "disable your antivirus software" to "do a system restore", nothing worked. I had to work by executing processes directly from the Task Manager which I could still access by pressing Ctr+Alt+Del. I have an HP Envy (model from 2016) and as mentioned run Windows 10. However, I also use Classic Shell. After wasting one solid day's work on my laptop and having tried everything possible, I got the brainwave that it might be Classic Shell as it was a desktop issue. So I called up MSCONFIG from the Task Manager and by doing that could access my System Information from where I was able to go into Programs and then uninstalled Classic Shell. The laptop booted completely normally after that, no more black screen. This problem occured for the first time yesterday after an automatic Windows update. So I do believe Classic Shell is no longer compatible. Btw, I uninstalled Classic Shell in Normal Mode, not Safe Mode. Hope this helps.
