Baking trim sheet struggle

spacecakes

hi so I'm studying games art and I have a reaaaallllyyyy hard time understanding trim sheet and I've got to the furthest point and now I'm stuck. basically I'm baking in substance designer after modelling in 3ds max, its keeps baking green. I don't know why, how or what to do to fix it it also doesn't bake the whole trim sheet only like a small corner of it which is really annoying. all I want to do is conquer this hell which are trim sheets and live my life in peace. any help? yes I've tried YouTube.
videos.

sprunghunt

Baking a trim sheet from a hipoly just like baking any other geometry. If your lowpoly matches up to your highpoly properly there shouldn't be any issues. 

What does the lowpoly look like? What does your UV layout look like?