Xbox Game bar is offline or storage missing error (Windows 10 v1803)

Really hate Microsoft right now!

The short version is that my H drive got corrupted last week, taking with it about 3 TB worth of games including a number of Microsoft Store UWP titles (Gears of War 4, all 130 GB of it!) plus some apps. Thankfully I only lost games (Steam, Origin and UPlay) which can be replaced. No save data was lost and nothing important.

Anyway, I reformatted the drive and set about redownloading part of my missing Steam library (which is spread across several different hard drives). I also decided to redownload Dead Rising 4 and Halo Wars 2 from the Store but due to limited bandwidth on my non-fibre internet connection decided to hold off until everything else on Steam was downloaded.

Only problem is that I now get a random error from the Xbox Game bar which claims it is offline and that the storage might be missing or unavailable. There is a link in the error window to the Store where I can choose to Reinstall the Xbox Game bar. Thing is that it will not install; it downloads and installs but then immediately reports that it needs to be repaired.

On checking the WpSystem folder, I found a sub-folder for the Xbox overlay with only two settings files and a load of empty folders. I deleted this folder and next time I was prompted to install the Xbox Game bar so I choose the C drive where Windows is installed. Well, what do you know, the overlay *STILL* insists on installing to H for some reason, still refuses to install and still pops up from time to time (causing the game to return to the desktop) to report that is offline! I tried reinstalling v1803 build 17134.1 as an in-place upgrade from within Windows the updating it to the latest 17314.5 build but the error still persists.

Odd thing is that the Xbox Game bar *is* working - pressing the Guide button on my Xbox One Elite controller or Win+G on the keyboard brings up the Game bar, sometimes with the error but not always - and the Game mode is visible in some games so I am not sure what this error is unless it relies on an internet connection (my current connection has been almost maxed out for the past four days continuously as I redownload games to the H drive).

Has anyone else ever come across this? I did some research on Google and found out that Windows assigns a new VolumeID to a reformatted drive and that this can confuse (surprise, surprise!!!) the Microsoft Store which is looking for the old ID. If that is true then I am shocked as I wonder how Microsoft can code something so poorly that gets 'confused' if you reformat a drive and then try to download the same apps and games back to it. Steam does NOT have this problem!!!

Just a quick update... I managed to fix this issue by using an admin Powershell to reinstall all the base apps again. The error has now gone and the game bar now works as before.

The Microsoft Store still utterly sucks though. I've lost count of the number of times that games have failed to install, usually stalling or halting at the last hurdle. I have been trying to reinstall Forza Horizon 3 for the past three days for example; it was stated as 55 GB at installation but it kept switching between installing (with the progress bar not moving) and downloading such that it was showing at 70 GB at the point I decided to cancel the installation, which was a full day after it had passed 55 GB. And when you do that you lose EVERYTHING that had been downloaded.

Absolutely infuriating, especially as I do not have a fast internet. If Steam, Origin and Uplay were like that then I would have given up on buying games on PC years ago. Microsoft really should be embarrassed. Where is the option to reliably pause a download, where is the option to backup a game and where is the option to validate or check a game for corrupted files and redownload them?