magnus

Sorry, never mind. Although the Windows Update screen told me I was up to date, when I went to reboot my computer (just in case), I discovered that not all the updates had been applied yet. It's installing OK now.

I'm having the same issue except that I've taken all Windows 10 updates, de-installed Paint.NET, and made sure there is no .NET 4.7.x installed. When I try to install Paint.NET it complains that I don't have a proper OS. The only thing I can think of is that I have Windows 10 Education installed?