hydraulic frac

I've build a 2D dimensional model of hydraulic fracturing based on the example on Verification Manual. I use the same data from the example. I build the model in CAE and edit it in input file to add cohesive element and cflow. however, the simulation stoped after 10 minutes indicating that a erro:"THE CRITICAL FRACTURE ENERGY IS SMALLER THAN THE ELASTIC ENERGY PRIOR TO DAMAGE INITIATION. THE DATA MIGHT NOT BE SPECIFIED CORRECTLY FOR *DAMAGE INITIATION OR *DAMAGE EVOLUTION.