Cannot open start menu

Hello,

I have relocated my Users directory during the installation of Windows to another drive using tutorial from this forum. Everything worked perfectly. Then I wanted to upgrade the build, however due to the relocated User directory, the update failed. So I edited the registry to point back to system drive (HKLM/SW/MS/WinNT/ProfileList), performed the upgrade and then turned the registry back (to the exactly same state as before). I can login, my settings is kept, however the start menu stopped working. I cannot open it anymore. Also notification center sopped working. Yes, if I create new user and relocate my files, it works however it is really annoying procedure (and I am curious whaťs going on - I have tested the even if do the registry change, don't upgrade the system a turn it back, the problem is there again).

Is there some kind of log, to find out why the Start menu doesn't open? What can I try to do to fix it?

EDIT: Looking at Windows event, there are errors that SAService and DgiVecp was not started due to missing file.

Hello, the start menu, taskbar, Cortana are very sensitive to settings, configuration and changes from Privacy in Settings to language configuration (Cortana).

I have just recently seen the start menu suddenly stop working myself.. just moving windows around on the screen, a sudden momentary flicker, then the Edge icon disappeared and the start menu stopped responding.

There are many threads on these topics.. just search the forum for (e.g.)
start menu stopped working
taskbar not responding
etc

It seems no one is clear as to why, but it is not simple to fix, so it would be of considerable interest to have a better way as many experience this problem.
An in-place upgrade repair is often recommended. (see tutorial section)

This is why using disk imaging to protect your system, your sanity, your data and save you time is so necessary.

This may be of interest:
Users Personal Folders - Restore Default Location in Windows 10 - Windows 10 Forums

Several people have encountered various difficulties when relocating user folders, and it's easy to make mistakes in doing so, crosslinking folders and drives or folders and folders.

My view? Avoid them. Leave them alone. I find they contain folders created by programs I install as storage and working space, which to me makes them 'Their folders' !

So I use my own folders on another partition for my data, away from the OS.
Those could be included in a library if I wished, of course.

With Win 10, it can be a case of 'Curiosity killed the cat'