Hey there Burce!
My name is Miguel Ángel and I'm an independent advisor, also a Microsoft user just like you! I'll try to help you today with your issue.
What you can do is going to Settings > Update & Security > Windows Updates and installing all the missing updates that your device may have.
After that, please use the Microsoft .NET Framework Repair Tool to check if the .NET Framework package is corrupted, damaged or anything else:
https://www.microsoft.com/en-us/download/detail....
Take into account that it may also be an issue with the app itself. Have you tried reinstalling it?
I'll wait for your reply! Don't worry, everything will be okay :)