02_muxing stuck at 99%

[CaptCam]

Hello and thanks for your time,

Basically I've been following the practice of (from 6:00):
https://www.youtube.com/watch?v=8qz8WFfZ...0s&index=6

Im Compressing some pretty large files into more manageable sizes for youtube. Im not compressing 8k but am using 4k footage so have changes the x264 bitrate to 100000.
FIle size as follows:

4992x2496 Equi-rec

The compression runs through until 99% muxing at which point nothing moves

WIndows PC with latest version of Hybrid


Output txt attached


Cheers