Hi all,
took me a lot of trial and error. Eventough the 32 bit applications should in theory rung "up to 4GB of memory", Music Maker free and premium crash once you reach over 2.4 GB with Music Maker projects.
I've tested it on few OS's (Windows 10 1709, 1803 and latest one 1903 and it always crashes, I've simply was playing with way too many plugins. What happenes is that MM pre-loads your plugins in memory and occupies that memory space before you even click on play.
So it's more of an information to all MM users as I didn't find this anywhere (or anywhere obvious),
Hopefully this will help someone in same situation as I am.