This happened back when the latest version came out, but I still have not seen any complaints about it, so I decided to complain about it myself. I will try to be as helpful as possible to everyone here so that we can work together to solve it.
Upon loading Paint.net, it asked me if I would like to install 3.08. Of course, I said yes. This was the last time that Paint.net worked for me. It said something about missing some file that was supposed to have been located in the Staging folder. The name of this file is PaintDotNet_673333360.msi.
Now onto the parts that I know.
I have uninstalled all old versions completely. at first it refused to uninstall from add/remove hardware, so I resorted to taking it out from the registry. I found every key that was related to Paint.NET. Currently there is not a trace of it in my system, not even association files.
My .NET Framework is not the problem. To make sure, I uninstalled it and reinstalled it. Still no dice. If anyone knows of a fix for this, I appreciate any help, since Paint.NET is the only "high quality" image editing program that I know how to use proficiently. Without it, all I can do is sprite in Paint.