I’ve got that when exporting intermediate/ProRes mov with fade-in and fade-out transparent images with Titles in second video track. It’s noteworthy I can export without crash H264 Main or High Profile mp4.
Transparent images are done by using File -> Open other… and then choosing “Color” in “Generator” -> Preselection “Transparent Title” (translated from french interface) and Titles using Title from Filters.
Rushs put in timeline are AVCHD mts or QuickTime mov.
I would also like to add that I can export successfully when my editing doesn’t contain titles at all and I get the same export failure when using transparent png images done in The Gimp as an alternative.
This bug is randomly reproducible with others codecs in different containers (almost every attempt with ProRes or DNxHD in mov and less often with h264 in mp4 contrary I stated before) on my platform (OS X 10.11.6).
I can help to debug if necessary.
Here is a link for a very short project with only one title and OS X crash logs (ProRes and DNxHD in mov export):
I used crf 20. It seems the size file difference is linked to rate control setting. MediaInfo analysis rather indicates Constant bitrate while I set Average Bitrate (?). So, I will try Quality-based VBR with crf set in Other tab.