Windows problem. I have a program running in dos mode, I already set the config.nt but still there

Question

I have a program running in dos mode, I already set the config.nt but still there is an error. The error is.. 16 bit MS-DOS Subsystem...
H:\ip\MRK1.EXE
The NTVDM CPU has encountered an illegal instruction.
CS:20d9 IP:c411 OP:fe268907 5e Choose 'Close' to terminate the application.

Please i need help for my program to run and work properly.

Thanks & Godspeed