There is so much wrong with your circuit, where to start? None of its problems are the fault of the simulator...
You need to limit the current through the photo diode by adding a current-limiting resistor.
Connect the gate of the NFET to pin 4 of the opto-isolator.
With only 10K pulling down on the gate of the NFET, the turnoff will be very slow.
The gate of the NFET will not stand 50V, so reduce the 50V supply to something like 10V.
The lamp load should be between the drain of the NFET and the positive power supply.
Why do you need a 200V power supply to light a 12V lamp?
Do you really need the opto-isolator?
Look up the data sheets for some real parts before you start playing with a simulator. GI,GO.