Mocha 2021 crashing when using GPU rendering

Mocha Version 8.0.0 build 613.gf8d98fc7fa3b, 10th November 2020
Avid Media Composer 2018.12.8
MacBook Pro 15inch, 2019, 2.4Ghz Corei9, 32GB DDR4, Radeon Pro 560X 4GB, Mojave 10.14.6
I am getting constant crashes with this combo when GPU rendering is turned on. Sometimes Mocha will crash when it’s trying to open, but it will ALWAYS crash when closing Mocha, which then in turn crashes Avid and upon reopening nothing has been saved, even if I have saved the project prior to closing Mocha.
I’m using the remove module and the remove sticks and can be rendered within Avid when just using the CPU sometimes, although I have had some crashes doing this too.
I’m finding that regardless of whether CPU or GPU is selected I can’t export a rendered clip and I get the error: “Failed to open file:”". The file may be missing, corrupted, or in an unsupported format.
I’m working on Prores 422HQ footage.
Any thoughts? It’s unusable currently.

Hi Andi,

When you’re trying to export your rendered clip, make sure there’s a keyframe number for Quicktimes. Can you try adding a keyframe of 1 for example on your export menu out of Mocha and seeing if that fixes your issue?


Hi Mary, thanks for responding, I take it by export menu you mean the Export Rendered Clip option from the File menu? When I open that I get a dialog box like the one attached

Once I click the Quicktime button, I choose where to export it to by clicking choose - desktop just for this test! Clicking save on the choose window brings me back to the attached export dialog. I then hit ok, and that’s when I get the error. I’m not given the option to add keyframes or even choose codecs etc. I can export a TIF sequence but that’s no good for me, really I want to keep it all rendered within Avid.
I am still getting multiple crashes on start and on close, sometimes I can force quit just Mocha but sometimes Avid needs to be quit out of too.

Interesting, you should get a second dialogue box after you click OK.

Can you email me your mocha log?

Thanks Mary, have just pinged you an email.