To those out there with the 121003 and 121010 errors I have found one solution. I use AdGuard on the system, not just in the browsers. I decided to try starting Solitaire today with AdGuard disabled (right-click the icon on the task bar or in the tray and select 'Disable Protection') and it all worked like it used to . No errors of any kind and even have events back again. It seems an update to Solitaire around three months ago made a change to their advertising in the app. I pay for the Premium Edition so there's no ads anyway but they changed something as the errors showed up in late April for me. Guess they don't want to tell you about a change to the ads being pushed to you.
AdGuard, when installed on Windows 10 will block ads in many browsers and in modern apps like Solitaire, MSN News, etc. There may be other ad-blocking software that might cause this issue also.
I hope this helps some of you. This has been a very frustrating few months with Solitaire with no real help that I've seen from Microsoft. They know what they changed but they're not talking.