Hi Shadow Wolf,
I had a similar problem going over to Win 10. I tried replacing the Objects DP folder with the Objects DP folder from a basic install. It worked so I assumed the problem was with the number of objects. That now seems not to be the case as I've moved most of the DP files across from the old folder to the new one without getting an error message. Just to allow the sim to get used to more files in the Objects folder I started it after adding about 10 DPs.
This was with one install. Starting another install in Win 10 gave me no problems either with the sim or MB, but that was on a different drive so there may be a few variables there.