Morning Matt, I've been at this for a couple of hours now. It's frustrating. I still have nothing conclusive, but, have found that it has nothing to do with the startup option, as far as I can tell.
In all of my many tests (that all crashed) I got the attached, just once, from Windows.
My new theory is that the server icon in the tray is doing something different.
Even with startup options set to MC+Server, if you close MC using the red X in top right, then try to use the server icon context menu to "Show Media Center", the program shows, and promptly crashes out of sight.
If I close using the red X and show using the pinned taskbar icon, it doesn't crash. I went through that at least a dozen times... Click X > click taskbar icon > click X > click taskbar icon and so on... no crash. Do that several times, then do a click X > left click server icon > show media center. Crash.
The library I was using contained no files. I have sent to you via email.
Also... Without question, if you clone a library, the clone does NOT use its own set of auto import rules. Change the rules in the clone library and they persist in the original, and vice-versa. This might be considered a bug?
-marko