NTVDM CPU has encoutnered an illegal instruction

Hi,

I'v been using the Abaqus command window to run my jobs without any problems.

Today, however, I suddenly got the following message:

Intel Visual Fortran Compiler 9.1 Build Environment for 32-bit applications - abaqus job=eightchain user=eightchain_Jaumann
The NTVDM CPU has encountered an illegal instruction.
CS:117a IP:0204 OP:63 65 6c 27 3a Choose 'Close' to terminate the application

The header of the message says: 16 bit MS-DOS Subsystem

 Has anyone had a similar problem before???

 Thanks,

Andreas