hello

I have a prusa I3 from makerfarm, it have work goood for me, but now after a while something strange is happening,

it wont print the first layer, the extruder stops to press the filaminent trhu the extruder and hotend, it is not jamed it is the stepper motor that stops,
then when it comes to the second layer it starts again?

any clue what is going on?

best regards kaj