@siucdude, I found a Pine64 forum post about this,
https://forum.pine64.org/showthread.php?tid=10424
which points to a Gitlab thread about it,
https://forum.pine64.org/showthread.php?tid=10424
Hi there,
I have this problem while installing UT from a Debian system.
Not sure if I'm stubborn or that I went to bed and wait until the next day, but the fact is that while the phone was on the Recovery I run again the installer and things went smoothly.