Shouldn't but it did. I am running under sream as the admin, and it was the firewall that caused the problem. I got a pop up from my Firewall/Antivirus that detected a change in simpleplanes.exe and then SP locked up.

I had to disconnect from the internet, disable the web monitoring part of the firewall, start SP offline, exist SP, then turn everything back on and restart SP. At that point the exe files matched and everything's okay.

Firewall shouldn't affect it unless you're trying to download it, try running steam as administrator assuming that's your platform