Dataset FORC with *ERROR:increment size smaller than minimum

Hello,
I’m running a static calc. with
*ERROR: increment size smaller than minimum
and i got a dataset FORC in the last timestep / result with displacement
when i have no error, there is no dataset with FORC.
Why i get these dataset ? what is the information of it ?
is there a relation between (external reaction) force and the *ERROR?

edit

in *NODE FILE
the variable RF is not activated.

thnx in advance
wbr dichtstoff