I'm excited to get my hands on this pack of plugins. Thanks, Curtis!
The reason I found this in my search is that I was looking for an easier way to get rounded corners. When I first installed it, it crashed when I tried to use rounded corners. Then I realized I was using only .NETframework 3.0, so I installed 3.5. I'm on Paint.net 3.36.
Now after finally getting .NET installed, I'm still having the crashes when I start to use the rounded corner utility. I've tried 4 or 5 of the other utilities in this plugin pack, and they all seem to work fine. Here is the error log: