I can't believe the number of problems we are seeing associated with this most recent cumulative update and its' immediate predecessor.
I think that for the most part many of us sail blissfully through them with out any problem at all, but.....
There seems to be just or almost as many who experience various problems and they seem to be mostly associated with some type of corruption in the user profile.
I have also switched users. The other user has the start menu working just fine
Since it seems to impact the user profile of the user who is logged in at the time, I think I'll create a second local admin user just to run Windows Updates from now on, just to be safe (maybe)
Is there any other way to access programs (apps as they are now called) other than via the start menu?
I don't believe I'm going to suggest this, but......
If it helps, then it helps. Maybe it will get you over the hump temporarily until the next round of updates either fixes your issue or breaks something else.
Consider installing Classic Shell from here
http://classicshell.net/
It's a shame that someone would need to resort to that to simply, make their computer work again but many people use it and seem to like it, so I thought I would pass along the possible option.
The other option is of course to create a new admin user and copy your old profile items over to the new profile, which is a bit of a pain but not too difficult
http://windows.microsoft.com/en-us/windows/fix-corrupted-user-profile#1TC=windows-7
The Windows 7 instructions remain pretty much the same for Windows 10.