Sorrow's End map freezes when I move starting hero to the right a few steps

Hello. This is my first post here, but I plan on being much more active on this site because I love HoMM 2 and I'm very interested in modding it!

Crash #1

Where does the crash occur? & What did you do right before it occurring?
The game seems to crash every single time I move my starting hero to the right a few paces. I don't do anything besides turn on HoMM 2 Gold via GOG Galaxy, load up Sorrow's End, and move to the right.

Does the game display an error message when the crash happens?
No, it just 'freezes' - it does not crash to desktop or display any error message.

Can you reliably cause the game to crash? How?
Yes, read above

Were you running the game in fullscreen or windowed mode?
Tried both.

What operating system are you using? What version of Heroes II is Ironfist installed over?
Windows 8.1

Crash #2

Trying to run ironfist.exe doesn't work - it always crashes.

When running ironfist.exe as administrator in compatibility mode for Windows 95, the menu works but I get the following crash and error message upon starting a map, specifically Sorrow's End:

Unexpected Program Termination

DirectDraw Error:

'DDERR_GENERIC

File: 'F:\h2xsrc\Source\wingraph.cpp'
Line: 522

Sorry if this has been answered before, but I couldn't find a solution. Thanks for introducing this cool mod and I appreciate any help.