MOGRTS crashing Premiere '21 - and Rendering as 'offline'

My Premiere '21 project containing multiple MOGRTs elements crashes on open, before the blue media bar loading has completed. I get no error, but the program becomes unresponsive. Also, before the crashing started, when exporting samples I was getting "media offline" renders, despite the MOGRT elements previewing and rendering properly within Premiere timeline and program window. Checking the "use previews" box in export dialog didn't seem to help.

Of course - I'm on a deadline for next week, with multiple deliverables. The main issue is premiere crashing, because I have a full 30-second edit that I can't render out, view, or share in any way!

Any help offered would be greatly appreciated!

AE v18.2.0

PP v 15.0.0

For what it's worth, I did not create the MOGRT files myself - and I've reached out to the internal team that built them for help also.