So I’ve found when adding a deform node to a model, if I choose Path for deform type, then Mask for path type AE 15.1.2 crashes (gets thrown to “suspended” status in Task Manager (Windows)).
However…If I choose Path for the deform type, then set the Mask Layer, THEN set Path Type to mask everything is fine.
So there’s something about the selection order. Selecting the first way I described cause AE to hang (little green leaf in Task Manager).
Selecting the second way is fine.