This configuration variable lets you work around the problem addressed by ECN-4837, which is:
After setting event-action to event-action-fail-terminate in a .NET control's event procedure, and then exiting the event procedure, format 2 accepts were not consumed when the program was running through the Thin Client. This was different from the run-time behavior.
To work around this problem, set the ECN-4837 configuration variable to TRUE (ON or 1).
ECN-4837 TRUE
The default for this variable is FALSE.