Cannot install games on my game pass ultimate app or windows store.

You can only play games via the cloud that are both part of game pass, and you have a game pass ultimate subscription

You cannot play random games from the Windows store, you have to install anything not part of Game Pass

I'm assuming you mean the Xbox beta App, so you can play games on Xbox game pass for PC or Ultimate. You need the latest Windows 10 version to be able to install the app, there is no other way. Also that app is only so you can find and install the games
from game pass easier. You can still find and download the games from the Microsoft store app, but they may not work without the latest version of Windows installed.

There are a couple things we can do to find out where the error is.

First step would be to check your subscription. If you go to your
Microsoft Account page, check under Services & Subscriptions. Verify that your Xbox Game Pass for PC or Game Pass Ultimate is still active.

Are you able to install any apps from the Windows Store? The Xbox (Beta) app uses the Windows Store to install, so if you're able to install other apps there, it's worth checking if you can install the Game Pass games directly from the store, to see if
it's an issue with the Xbox App or the Windows Store.

Let us know on those, and we can figure out the next best troubleshooting steps.

Thank you. I uninstalled and reinstalled the Xbox App and Windows Store. I did a repair and reset of both apps while signed out. I did the Power Shell reset of the Windows Store.

I checked all updates were installed on my PC.

I also discovered that I cannot play a game that I own. Same error as the game pass games. So it looks like Forza 7 (own) and my Game Pass Games will not launch on PC.

So on your PC you need to make sure the
game pass ultimate account is signed into the
Microsoft store app, You might want to try installing the
xbox(beta) app on windows as well and try downloading from there.

Not all of the game pass games between Xbox and PC are the same, the xbox(beta) app will show you all the available and installed windows game pass games

US xbox(beta)

CAN xbox(beta)