Hi Samuel,
You may have already solved this problem. If not, do you have any still images in your sequence? I have found that if I have high-res still images in a sequence it causes strange export problems. The sequence will play fine in PPro, but just won’t export without crashing. No matter the export settings.
I now reduce the resolution of all the stills in the sequence and the export goes well.
The original files are 8000 x 5300 or so. I typically reduce them to about 2500 wide for an HD sequence. This still leaves room for some pan and scan or re-framing.
Jeff Jones