Connector Failure Assembled Beam Type

I am having problem of connector failure. I need to know whether it is necessary to define upper bound and lower bound value for dislocation. i want to use only force /Moment criteria for failure. what will happen if i put 0 in upper bound and lower bound for dislocation. and provide only upper unbound force value. one more thing when i do that CTF output vanishes from field output. how can i fix this.