[Davy Force]

FOUND AN EASY WAY FOR THIS FOLKS!!

Select bottom mask first (mask 100 or whatever) then multiselect (shift) the first mask (mask 1) so youve multiselected in a reverse order. CUT the selection (to delete paths) then paste back into same layer- Mask later order will now be reversed-
your welcome!

[Davy Force]

HI THERE
After having this issue as well- and trying EVRYTHING listed here- still had the same issue-
Finally zeroed in on the culprit-
an audio Sony Pitch filter set to high quality Speech 7 mode locked up the render every time. When using lower settings got it to render. So its not just bunk GPU and memory cache settings in some cases but buggy audio issues as well.
ARGGG SONY!!