I mentioned the issue of lack of repairability of store apps - such as the Xbox app - in another thread after I had a bluescreen during an update of the Xbox app and then it would just immediately close with an error logged.
There are many fixes for common errors with the Xbox app like the reset option in the app info, or re-installing gaming services, and I even tried the "fix problems using Windows Update" recovery option but they all left the state of the Xbox app exactly as it was before - there's no option to easily remove all data to force a full clean app installation as has been possible with regular programmes for ever and with phone apps.
In the end a new version of the Xbox app appeared in the store and installing this fixed the issue - I don't think the issue was simply a bug in the previous version but perhaps the process of installing a newer app version fixed whatever was causing the Xbox app crash when nothing else did.