I found the problem, after looking at the log I realised that I did not have enough disk space. The weird thing is however that every time it failed to unpack because of insufficient disk space it would delete the files and start downloading it again.
I had 20 gb free but I forgot how large the unpacked map files can be, obviously once I cleared some disk space by temporarily moving some liveries out onto another drive it installed no problems. Lesson learned: check disk space.
It would be nice though if after unpacking and detecting not enough disk space it could give a warning so that you don't perpetually do the same thing over and over wasting data (this might just be me though). I'm on a limited mobile data plan as I live in a rural area with no other option and have basically blown through my cap for the month. On the bright side I have an updated Persian Gulf map.
Thanks for reaching out though. :doh::joystick: