Hi,

to the point. When playing MM9 my mouse tends to move unexpectedly about 90 degrees to the right and about 45 degrees up OR down. The issue is most likely caused by some interaction of the game and my new GM650 mouse as a different mouse (A4tech F4) has the same only it jitters to the left. Both mice (mouses? in this case) have DPI profiles and options.

Playing on Windows 10 64bit, Unofficial patch 1.3a. Everything else works perfectly.

I have already tried the GOG recommended turning off mouse acceleration in Windows and remove DPI scaling.

Please, does anybody have any idea on how to solve the problem? I don't want to use loud backup mouse if I really don't have to.

Thanks in advance!

I have exactly the same problem (and several others) when playing the game in Windows 10, but not when I use the same mouse playing the game on another computer on which I have Windows XP SP3 (where the game runs absolutely perfectly).
Can't help you much with the problem, though, I am sorry. :-( Haven't found any solution myself either, so I am eager to learn if there IS something that can be done about this.
I have a Logitech MX Master 2S mouse.

I have problems with mouse jittering too. It's insane, the game has no idea how to read mouse input. I've read about disabling mouse acceleration in Windows, I'll have to try it out.

Other than that: I think that this game should explicitily have a warning on every store that it's a BROKEN PRODUCT and shouldn't be expected to work.

I mean generally speaking when you buy a game that's 30 years old you're expected to do some fixing mate

Thing is you can't fix it.

sure you can, there was this topic called "all might and magic 9 fixed in one place" or something n it fixed the mouse thing as well. not sure if links there are up anymore but yeah you can fix any software issue as long as you try hard enough.

Files don't exist anymore, and I don't see anything about any mouse problems mentioned anywhere there.

change in autoexec.cfg "MaxFPS" "0" to "MaxFPS" "75" and it might fix this and mouse problem

try that I guess, its very trial and error since its been so long but I'm sure you can find a solution but it might take a while (if this doesn't work)