It should!

Are you getting any console outputs?

Is it behind another window/on a turned off secondary monitor?

I haven't been able to test it in 4.3. Are you able to see if the issue is present in 4.2 as well?

Hm, I haven't tried it in 3.x. After having Googled around a bit, I suspect this has something to do with meta files. Not sure how to solve it though. Shader Forge should be 3.x compatible in the end, so I'll mark it as a planned fix. Are you able to test it on 4.x?

Hi! I can't seem to be able to reproduce this bug. Did you just change the mesh, and that's it?

Haha! That's awesome, didn't know VS had an fbx viewer. I suppose VS is your default program to open .fbx files in :) If you want to switch mesh, click the little circle to the right.

Purely a mac related issue it seems, I'll look into it! (Sadly I'm unable to test it myself)