I've run RegCM from May to Oct. of 1973 with the 60km resolution(ds=60) and 200 seconds time step(dt=200),but got model crash with the "floating exception" error. I've tried it by 150 and 100 seconds time step(dt=150,dt=100),as well as all other lateral boundary conditions(iboudy),but there is no improvement. Please tell me what can I do now?