Installed Cura LE now can't connect to old version

General LulzBot TAZ
1

I recently installed Cura LE 4.13.10 and updated the firmware from inside Cura fo use on my Taz 5, but now my ABS prints aren’t sticking to the textured PEI plate like they did when I was using the older Cura 17.10.
I hadn’t used the printer in a while, so when I tried printing again, the parts weren’t sticking to the smooth PEI plate, hotend set to 240°C and the bed at 110°C. To fix this, I bought a textured spring steel PEI plate, and small parts (about 1" in diameter) stuck really well—amazingly well.
However, after installing Cura 4.13.10, the parts no longer stick at all. I thought about going back to the older version of Cura to see what might have changed, but when I try to use it, the older version won’t connect to the printer.
Does anyone know how to get version of Cura to reconnect with the printer?

Your help is greatly appreciated,

2

Sounds like you didn’t record and restore your Z offset when you flashed the firmware.

Do a basic Z offset calibration. Post up pictures of the underside of the first layer tests if you need help interpreting them.

3

If you don’t have multiple Taz 5’s, you can optionally commit the z offset to your start gcode using the M851 command. That way you can never lose it.