Microsoft Store and various apps don't work in Windows 10 version 1903

"Ever since I downloaded 1903 I have not been able to download anything from Microsoft Store or Update Computer"

Does Update Computer mean Windows Update?  For me Windows Update works for non-Store updates.

Some subfolders of C:\Program Files are visibly owned by Trusted Installer.  C:\Program Files\WindowsApps denies permission to view who its owner is, but I have a feeling it's also Trusted Installer.  Administrators don't get to see what Trusted Installer owns.

There is supposed to be a subfolder of C:\Windows for the Store, but I'm missing that subfolder entirely.

On some other computers with 1903, the Calculator still works.  Whatever damaged the Store on this one 1903 computer, the Calculator doesn't work (along with the Store itself, etc.).

There is no immediate subfolder of C:\Windows with "Store" in its name. What folder are you referring to? They all are deeper than that.

Also, I have no****SharedLibrary.dll or mt100_app anywhere - not even inside a .zip.

(1) I realized a tad late you meant the snarkiness was in your 2nd sentence, not mine...

"(The second sentence is a bit snarky, I don't really think you knew that reason for a system image backup, but your idea is good anyway.)"

I was too pleased in what I had written to consider changing it. Anyhow, you said my idea was good, & good is good enough for me. OK - what "reason" are you referring to? In addition to recovery of a working full installation (as/of the date the image was made), an image backup can be mounted. Then, individual files can be copied off it. Also, it can be used to move an installation from one drive to another, as in the Da Costa article I posted earlier.

(2) "Right, that means it wouldn't really be a fix."

Sadly, it is too late to make one now to fix your current problem. But, if you made one now, you could get back to the current problem, if things get even worse. I do like to have a reasonably current image to fall back to before doing an upgrade-install or even an in-place/over install (which is much the same thing).

" My Outlook and Firefox databases would be reverted to the time of the backup."

Are you sure the databases aren't on their servers? I do know, there was no disruption in MS Mail, not that I detected - not from a system image restore or even from a clean install. (Maybe I should go reread Greg's post about that). MS Mail interfaces with an on-line Outlook.

(3) "Yes my other computers were moved from Japan to Canada"

OK. That proves Region is not the problem, if the computers in Canada are fine.

(4) In case Ladyhawke2020 (Kelly) is not enough company for your misery, try this guy...

https://answers.microsoft.com/en-us/windows/forum/windows_10-windows_store/windows-10-microsoft-store-wont-repair-uninstall/9cc9fc5f-7ae8-46bb-ae9e-bbb44ceb9d01

Windows 10 Microsoft Store Won't repair, uninstall, install or reset. How can I download and Install Windows Store from a standalone package?

That's the first thing I ran into in a search for "9WZDNCRFJBMP-MICROSOFT.WINDOWSSTORE". I still think, once the Store is successfully installed, your problem will go away. All the other Store apps come in through the Store - not through Windows Update. Too bad no one answered wmcole's question, "How can I download and Install Windows Store from a standalone package?". I'm still looking.

I also continue to think the computer must have some kind of a link to your Microsoft Account or the Store won't work. But once you open the Store & sign in, it should do that automatically.

"There is no immediate subfolder of C:\Windows with "Store" in its name. What folder are you referring to?"

Now I cannot find the command that I executed before, which output an error message about a missing file, where the pathname was under the Windows folder and I was missing the entire subfolder.  Sorry, I don't remember what the subfolder name was.

Now, I'm trying another time to register the WindowsStore app, and it says that a file name AppxBundleManifest.xml specifies some other file which doesn't exist and cannot be opened.  But I can't find a file named AppxBundleManifest.xml so I don't know what it's trying to open.

Also now, I read that some Store applications are capable of being repaired from Settings.  But now, in Start - Settings - Applications, the Calculator app can only be shut down or reset or uninstalled.  There is no option to repair it.

OK, there are many Store files with a path name under C:\Windows. The command you executed, maybe WSReset, meant to do a repair of Store files. But the files probably didn't exist because the Store is not installed well. Too bad the command won't go fetch them.

I've got no "AppxBundleManifest.xml" either. It must come in when you try to register the store. I guess, although the registration fails, it cleans up after itself & deletes the file.

That's what I see for the Calculator too. Looks like a reset will constitute a repair. Too bad you can't get into the Microsoft Store that way. It has the same options.