StartMenuExperienceHost.exe stopped working ...

If it also happens with a new user account, resort to an in-place upgrade repair install.

MS update just dropped.

I went through this routine snagged from MS site:
Note: My user account has admin privileges + the console routine is also explicitly admin.

Code:

-- Command Prompt (admin) 
-- 2024-04-09

dism.exe /online /cleanup-image /scanhealth
dism.exe /online /cleanup-image /restorehealth
dism.exe /online /cleanup-image /startcomponentcleanup
sfc /scannow

--- completed 5:14pm 
--- restart
--- 
--- Powershell (admin)

Get-AppxPackage -AllUsers Microsoft.Windows.ShellExperienceHost | Foreach {Add-AppxPackage -DisableDevelopmentMode -Register "$($_.InstallLocation)\AppXManifest.xml"}

--- completed 5:19 PM 
--- restart

I'll report back if that's enough. If not, proceed with creating a new account etc.

Edited to add:
Did the new account drill, then went back to my old account.
We'll see tomorrow.

Does it happen under the new account?

Remember the idea of creating the new account was just for test purposes with the intention of deleting it afterwards, not necessarily to migrate to it.

This started happening after I installed the april updates, cumulative, malware tool and the .NET update. There were also some automatic UWP app downloads after the reboot, but only the components marked as system components in the Store. The Store settings are still set to forbid automatic app updates, but that doesn't apply to the system components anymore, things like the video encode plugins or feedback app. One of those updates references a "UWP desktop", or something. Could this be the cause of this error, and not the april's security updates?

Anyway, I ran the all the console commands in post #13, as admin (I'm always logged in as a normal user), no corruption reported. That was the second time sfc/scannow was run after the updates, no change. Then I ran the powershell command, copy-pasted, in admin-level powershell I accessed by right-clicking the startmenu. That should be ok? I was online the whole time those commands were running. Then I did a full power cycle - shutdown and restart. This still keeps happening whenever I use the startmenu or right-click items pinned to it. I've run all the commands again just to be sure, online. This time after running the powershell script I saw the taskbar refresh, the icons flashed. The reliability history seems to display the events with a certain delay, maybe 10 minutes or so, so I'll report later about the results.

Edit: Still keeps happening. I ran the startmenu troubleshooter and it reported two problems it couldn't fix: the same as in OP's post, and tile database corruption. The applications that apparently need re-installing are the "Microsoft.Windows.ShellExperienceHost" and "Microsoft.Windows.Cortana". You need to hover the cursor over the blue line of applications that need re-installing to see a popup that tells which ones they are.



- - - Updated - - -

I have now tried logging in with my admin account and running the powershell script there whilst online, still by choosing the admin option in the menu just in case. I haven't used the startmenu itself yet, only the wifi one, but soon enough I'll know if the spell made any difference. A laptop that I installed these april updates to doesn't seem to exhibit this bug for some reason but I ran the start menu troubleshooter there anyway, after the updates, and it reported the same problems which it couldn't fix. They may be totally unrelated to this. The laptop has a microsoft account in everyday use, in case it matters. My main computer doesn't.