Ok, combing through an earlier thread, about MacOS X High Sierra:

http://moi3d.com/forum/lmessages.php?webtag=MOI&msg=8592.3

I followed the fix there and it seems to have done the trick. And now MoI is launching and running good as before.

Thank you Michael Gibson for posting that fix in that thread.

Hi Lestatdelc, yes it's a side effect of updating the OS, I'm glad you have it resolved now. I've also come out with a v3.2 release for the Mac version which has that setting needed to run on High Sierra changed by default. You can get the updated 3.2 version from here: http://moi3d.com/reinstall.htm

It also shouldn't be an issue with the v4 beta release which you can get here: http://moi3d.com/beta.htm - for v4 the Mac version has a lot of changes, it's a native compiled version now and doesn't use the "Wineskin" mechanism anymore. It is my hope that v4 will not be as sensitive to changes in new OS releases but we'll have to see. Wineskin is very sensitive.

- Michael

Thanks Michael.

I will check out the beta 4.

Is there a thread about what's new in the 4 version (particularly for us Macusers)..?

Hi Lestatdelc, there's a collection of the v4 beta release notes here:
http://moi3d.com/wiki/V4Beta

There's lots of things improved for the Mac version, like Retina support, 64-bit, full screen mode, trackpad navigation, ...

- Michael