Andrew,

In "Loop not closed at point 120.079/259.997." we can not use the coordinate as such.
With my preferences I would need 120,079;259,997 as a valid coordinate to enter in the command line.
I do this 'translation' in between in Notepad.

Not that personally my boundaries are frequently off ;-)

Reported by <OttoZ> in:
https://www.qcad.org/rsforum/viewtopic.php?f=89&p=38836#p38829
//'Die Koordinaten lassen sich nicht kopieren, sonst könnte man zur Fehlstelle springen.'
//

In all cases the "/" is not a valid Cartesian coordinate separator.
The dot at the end of the sentence is also not so common in QCAD.

Regards,
CVH