residual computation error

when given for solving, an error occurs as shown below:

error:
time: 0.005389521413017638
Error in residual computation
extrusion_coupling_operator_interpolation_failed
Geometry:1,boundaries,459,666,destination coordinates[.......]
failed to evaluate variable
variable:A0z_emqa2, defined as A0z
Expression:d[(-test(-Az+A0z_emqa2)*lm5_test(lm5)*.......
Last time step is not converged.


pleaze help me with what this means.
Also if necessary I will forward the motor simulation.The simulation is helped with FEMLAB also.