Problem setting up bootcamp 2012 MBP Mojave

[Rico Muerte]

I have a non retina 2012 MBP with 2 x SSDs - 500Gb boot drive, 1Tb files drive:

Upon beginning the process for setting up bootcamp I got the following message:

It's saying there is not enough free space for the partition despite the fact there is more than 350Gb available on the 500Gb drive!?



Also Im using a 16Gb USB stick for the windows iso & I also got a message saying there was not enough space on the USB despite it has been erased & formatted:

What am I doing "wrong"?!

 

[Rico Muerte]

Thoughts? Ideas?

 

[Yebubbleman]

Something is messed up with how your drive is partitioned. What I might do to remedy is do a full Time Machine backup of what you have, then do a clean installation of version 10.14.6 of Mojave and migrate everything back from your Time Machine drive using the migration assistant (this ensures that only your data moves back and not any oddities from how your drive was formatted). Then, after you've confirmed that everything is fine (and it most likely will be), you'll probably be able to re-run the Boot Camp Assistant and have it work just fine.

APFS is a tricky little female canine sometimes. It definitely has added to disk management complexity over how things were with HFS+.