2.8/2.9 is the linuxcnc version.
2.8 is the current officially released version.
2.9 is close ish - it certainly can be used reliably.
I think you might be missing a library that pops up a message dialog.
If you run linuxcnc/qtdragon from a terminal, it might tell you the library names.
Something like package python-dbus.mainloop.pyqt5
Probing error - that should be a linuxcnc (not qtdragon) problem - sounds like your Z axes acceleration is low. Strange it would be different with AXIS.
There is another probe gcode 38.4 that moves away from the work piece and trips on loss of contact. so probe g38.2 down, then probe 38.4 up, then rapid up. probably more accurate too.
linuxcnc.org/docs/2.9/html/gcode/g-code.html#gcode:g38
There is no guarantee that the line numbers displayed are exact in linuxcnc.
often they are right, but not always.
It's possible to trick linuxcnc to do jog while paused with external offsets - it's a bit advanced but it still doesn't allow origin changes while in auto mode.
We almost had proper built in Jog while paused... but that was a long time ago.
What distribution of linux are you using? Debian? The floating error messages should work in 2.8 - probably just missing the package.
If you could run linuxcnc from the terminal and post the output, maybe I could see the problem.
Chris
