FCPX 10.4.3 Reboots on Export

I have a library that appears to be damaged. I don't know why this should be, but I get that.
I created a new Event and imported a new clip and added a 10sec intro to it and then tried to export.
FCPX does about 200MB and then just restarts the Mac! This is a repeatable scenario.

Any suggestion to how to fix or track down the culprit?
Surely even if there was a damaged clip FCPX should just abort the process, without crashing the entire computer, no?

I am running on an iMac PRO with 64GB ram and nothing else open except the usual background apps.

What is the capacity of your system drive and how much of that is free space?
Same question for your secondary media drive.

System: 1TB SSD with 497GB free
Video: 20TB with 11.7TB free - Thunderbolt 3 connected Promise Pegasus 3

A number of iMac Pro users have reported kernel panics on FCP export, This needs to be looked at as a hardware issue by Apple.

If it is only a small number, do we know if this is a warranty or a design problem?

The two I work with don't have that issue. One is even running dev beta Mojave. I'd have an Apple retail store give it a good check up, see if there's some hardware issue, as suggested.

Thanks for the suggestion.
It only happens on a couple of Projects. Others export ok. It is rather disruptive to carry my iMac Pro to the store and then leave it there for days! I am going to try first to clone the drive after moving the library to the system drive, and testing the clone on different Macs.

They'll test it right there in front of you at the counter, they don't keep it for days.