Microsoft Solitaire Collection installed on your PC might be out of date, or the cache that is built-in for many days is working against the new updates in the game, or the internet is taking much longer to connect. Any of the above issues might be the reason for the Solitaire game not loading. You must check for the updates of the game in the Microsoft Store, install them. If the issue is not fixed then also, run the app troubleshooter in Settings, clear cache, reinstall the app, update the graphic drivers, etc.