Weird. What version are you on? (Also interested in stuff like 32/64bitness and your system RAM).
I've been able to run GM6 stuff on my Windows 10 machine just fine... some of it, at least (I think the executables that work were passed through the GM6-to-vista converter). Dracula 13 was made in GM8.1, so it should be compatible natively. (Knowing windows, that doesn't mean it is...)