Video appears to have exported but playing with VLC media player fails 3/4 of the way through

I am attempting to export a video about 35 minutes long, in High Quality 2160p 4K and in the H.264 format. I have tried to export twice. The first time, the video appeared to have exported normally (using GPU acceleration), but in playback in VLC media player, and the standard Windows media app ('Films & TV') the video fails halfway through. 

The second time, I switched to Software only as the renderer. It took 1/2 the time to export as the first time, and appeared normal, but again failed 3/4 of the way through in playback (note that it failed at a different part of the video).

I have exported before with GPU acceleration and all the other same settings, albeit not a video quite as long, in the past, with no issues.

How can I fix this? Thank you.