Nordic track A2250 is skipping and sliding. We replaced the belt but it keeps rolling even when off. Must hold on to bars work run on it

If you wish to get some details; check the site linked here. Pull up older posts. Surf for article abort treadmill.
http://electro-medical.blogspot.com/

It’s your motor controller.

Adjust the REED switch, test it, clean it, and tight the plug or connector very well.
2) replace batteries with the same type, same mark, same polarity
3)clean contacts spring with c. cleaner spray. buy it from some electronic store.
God bless you

see the video and proceed according, use the common sense.

God bless you

adjust the reed switch first, and after RUN the software calibration for diagnose and troubleshooting. see the diagram

God bless you

If your treadmill has had a lot of use, the belt has probably stretched and needs replacing. You can order a new one at Treadmill Parts

the motor controller is bad and needs replaced

My Nordic Track Treadmill A2250 is stuck on the 12% incline position and it wont go back down and I have tried to reset it by turning it off, switching the reset button to off and then on or even unplugging it several times. What would be my next move?

I had the SAME problem, several times, with my NordicTrack A2250 Treadmill.
Allow it to go fully up and then fully down several times, without turning it off. IT seems to "cycle" that way 3 times and then "reboots" itself and starts working normally, again.
I had to figure this out myself... none of the suggestions I read worked.