Cannot install games or play installed games.

I have been subscribed to the Microsoft Game Pass for PC for about 8 months and, over that period, have experienced no issues. Tonight, when attempting to play Sea of Thieves I have run into some massive issues and, after investigating, have found that this
is affecting ALL Xbox games.

The OS is as follows

Windows 10 Enterprise

Version 1903 (OS Build 18362.1016)

Windows updates complete as of today.

Here is the order of events.

1) When attempting to run Sea of Thieves the splash screen appeared and then immediately disappeared. The game would not run. I tried again, got the same result and restarted my PC.

2) I followed some advice on the forums that suggested that a WSReset might be in order. I ran this but there was no improvement.

3) I followed further advice to change my default region to US. No improvement.

4) I followed another suggestion to install any other Microsoft app from the store. I installed Netflix with no issue and could run the app.

5) The next suggestion was to reset the cache for Sea of Thieves. I did this and could still not run the app.

6) I attempted to reinstall Sea of Thieves. I immediately got an error as follows

Something Unexpected Happened

Reporting this problem will help us understand it better. You can wait for a while and try again or restart your device. That may help.

Code: 0xC03F6603

6a) There is a link on the error bubble which says "Find help on this". This takes you to https://support.xbox.com/games/game-setup/troubleshoot-games-windows-10 which
provides the message;

Hey, what happened to this page?

It may have a new location or may not be available any more. Try this:

6b) I then received a popup which asked me if I was happy with my installation but clicking on this says "This survey could not be found".

7) I uninstalled the Xbox app and reinstalled it. I noticed immediately that the install was still in error state. I attempted to reinstall the game but got the same error.

8) I reset the cache on every Xbox app. I then uninstalled them, ran a WS reset, restarted and reinstalled. The install was not in error state but immediately errored when I tried to install.

9) On a hunch I tried some of my other Xbox apps and received an error message stating that there was a file system error. This happens across ALL games. What I did notice is that the error message is trying to run the app from C:\Program Files but all of
my games are installed on the D drive.

10) I went into Settings > All Settings > System > Storage > Change where new content is saved. I noticed that applications were set to install to the C drive. I changed this back to D. I know I have not changed this myself so can only assume a Windows update
may have affected this.

11) I went back into Xbox Beta and checked settings. I made sure that it was attempting to install to the D drive.

Right now, I'm at a loss. I have tried everything I can think of. There are no error messages relating to this in the EventViewer. There's one error talking about an expired certificate and a small issue with the Volume Shadow Copy Service which is not related.

I've run out of things to uninstall and reinstall and the only other option is to do a full Windows 10 reinstall and, I have to be honest, I don't enjoy the games enough to commit to that since I've got plenty of other games on Steam which I still have to
play.

Any ideas before I just jack all of this Xbox Games Pass for PC in?

Many thanks!

:)