Posterior mean doesn't pass steady check command

I estimated a DSGE model using dynare. In order to check the results, I use the posterior mean of the estimated parameter values as the initial value of the model, and do steady; check; and stoch_simul; command without estimation. But Dynare reports error: The jacobian matrix evaluated at the steady state is complex. Does that mean the posterior mean does not make any sense and the estimation process is wrong? Is there any way to correct it?
Thank you,

Hard to tell without more details. Please post your MOD-file.