Volume Rebuild crashing

I'm trying to rescue an internal SSD on a MBP. It is a 1TB OWC SSD kit - OWCSSDAB2MB10K.

I have 2 SuperDuper clones of the SSD, one a day old, the other slightly older.

I have booted from these clones, and tried running the Volume Rebuild, but it doesn't let me, saying that TechTools Pro is running from the volume (i suspect as the internal drive is a clone)

So, i tried creating a techtools to go, which booted, then gave me the same error.

I tried connecting via Target Disk mode, and running TechTools Pro from another mac. I got the same message.

So, i created an eDrive and ran from there. TechToolsPro crashes after starting.

Any ideas?