I woke up to the same issue today. It's taken me three hours, but I found - well, stumbled upon - a solution.
1. Uninstall any taskbar addons
3. Install the Valinet Explorer Patcher latest release from https://github.com/valinet/ExplorerPatcher
Your taskbar will be back to the previous style (as in multi-row, resizing, add toolbars, lock/unlock) all re-enabled,
and you should have a Windows 7 style Start menu. You should now be able to:
5. Open Start11 and customize your Start Menu as you want. I'm running V1.47.
That ought to do it.
Note: I also uninstalled the latest Windows patch first, rebooted, then did the above. I have not rebooted yet - gotta get working - but fingers crossed, this will hold.
Hope this helps,