[Solved] Y-axis length error  

Y-axis length error

briefing:

Y axis hard to move

it honestly working before a octoprint update

Prusa info:
Prusa i3 MK3

Work perfectly since six month.

Work since one month with octoprint.

The day when everything changed:

today I updated my octoprint from the web interface.
the printer was on and connected to my PI during installation 

At the end of the installation no error.
I reboot the whole thing (simple windows tromatism but it was not necessary I think)

after that I wanted to launch a print, but at self-leveling the Y axis made a loud noise, then printed 4cm in height from the bed ...

I wanted to do a calibration from zero.
The problem was then that as the bed did not go to good zero the printer could not find the landmarks (at the time with the sheets of paper on the bed).

so I flash the printer to have no save parameters but same problem.

Then i use the manual,

the part on the motor is well positioned and no cable is blocking

while searching on the internet I found this error but only for the X axis.
There is no cable blocking the bed and it does not seem to me that the problem is due to a lack of oil on the axes

Some info:

When i try to make the auto check the error is

{

Selftest error !

Please check :

Axis length

Axis   Y

}

when i put the "auto home"
the zero of Y is where the bed is at boot

by turning off the printer and moving the bed sometimes I can move it without problem on 2cm then its becoming very hard has moved, there is no special area where it blocks.

the belt status for Y is at 250 (recommended between 240 and 300)