I simulated a n-type mosfet with following settings: device type mosfet n-type gaussian S/D doping density

source/drain length: 50nm source/drain nodes: 15
channel length: 35
oxide thickness: 2 nm oxide nodes: 5
junction depth: 20nm junction nodes: 30
substrate thickness 50nm substrate nodes: 10
device with 1000nm

peak source/drain dopng concentration: 2e+20/cm3
characteristic length along the channel 8nm’peak channel doping concentration 2e+18/cm3
substrate doping concentration 1e+15/cm3

Vg minimum -0.1V Vg maximum 1V number of nodes 23
Vd bias minimum 0.05V Vd bias Maximum 1V number of curves 2
Vb bias point 0V

The simulation runs well with other gate length and only give void result when channel node number is between 25 to 35 with a gate length of 45nm. I cannot change any of the settings and the result is required. How can I get over this?