I have that message (Install updates now or after exit?) and i chose after exit and the flowing error was appears:
I tried to Uninstall paint.NET first and the same message appears, my desktop have a new file called "pdncrash.log" download it from attachment area.
" Another thing: version 3.5.1 not in the download site "http://www.getpaint.net/download.html" please update the download link ( I have download it from Download.com)"
Please find a solution for my issue
pdncrash.log