I've installed/upgraded a few times trying to reproduce this and have not had the issue. A NullReferenceException is a very generic error and could be caused by any number of things. That's why the output log is so important, because it gives us an idea of what failed, where, and why.
The fact that your entire appdata folder is absent is definitely not normal. Just to be clear, what happens when you press the Windows key and then paste %AppData%\7DaysToDie into it and press Enter?
Please post a picture of that folder, and double check the log folder inside of that, if they exist.
Have you checked your system RAM / drive health to make sure things are good there? A failing drive or bad RAM could cause this issue. I see you have other open reports so I'm closing this one.