Applies To:
  • CitectSCADA 1.00, 1.01, 1.10, 1.11, 2.00, 2.01

This exception means that a DOS application is trying to execute invalid instructions. This error is fatal and you must reboot the computer. The DOS application could be a network driver or any TSR that is loaded before Windows is started. This error may occur as a side effect of a Citect crash if Citect is communicating on a network.

This happens when a trap occurs in Citect, as Windows will remove Citect from memory - while there is pending network communication. The network commands are not cancelled, so when they complete (possibly up to 10 seconds later) and try to access Citect they will cause the EMM386 Exception Error.

This exception can also be caused by bad network drivers, stack overflows, and bad memory. 

The Solution is to find the cause of the first failure. Run DrWatson and generate the trap and send the drwatson.log file in the c:\windows directory to Citect Support.