RSM producing segmental violation error

segmental error

hi users,

I am modelling the flow over an active fin ,used in warships to control roll motion i find that the model works with k-e but it is giving segmental violation error for RES model for turbulence can anyone tell me how to overcome this.One more problem encountered in k-e model is that i am getting negative Cl value for an angle of attack of 5 and -5 can anyone suggest me a solution for this.