TN3270E May Experience Unexpected Application Exception Errors

• Microsoft SNA Server for Windows NT, versions 2.11 and 2.11 Service Pack 1

SYMPTOMS

The SNA Server 2.11 Service Pack 1 Tn3270E Server may experience intermittent and random access violations.

If this occurs, the SNA Server TN3270E service will log the following event in the Microsoft Windows NT application event log:

   Event Id:5
   The TN3270E Service has abnormally terminated.

   EXPLANATION
   An exception (0xC0000005) has occurred that has caused the TN3270E
   Service to terminate.

   ACTION
   Record message and contact technical support.

CAUSE

The TN3270E Server user license validation routine was accessing the global queue of session control blocks without using a critical section to serialize access to the queue. This leaves a chance that while it is accessing a control block that control block could be deleted by another thread.

STATUS

Microsoft has confirmed this to be a problem in Microsoft SNA Server versions 2.11 and 2.11.sp1. A fix to this problem is in development, but has not been regression-tested and may be destabilizing in production environments. Microsoft does not recommend implementing this fix at this time. Contact Microsoft Product Support Services for more information on the availability of this fix.