Just put in a new sensor and transmitter and this is the message when I try to calibrate it (it’s off by around 30 so it needs to be calibrated). I have OB1 and Native selected in settings, tried un-checking one at a time then both, with no luck.
I’ve seen some other posts in the past with this same issue, but no answers.
I just started a new G6 transmitter, (prior one was 81, new one 8G) and got similar message in xdrip (impossible calibration slope). I had to uncheck setting in debug for Fallback to xDrip, then it worked fine without error.