Perfmon Trap or Winlogon STOP C000021A When Running Perfmon (180054)
The information in this article applies to:
This article was previously published under Q180054 SYMPTOMS
When you start the Windows NT Server Performance Monitor locally on a
computer running SNA Server and you pressing the "+" key (which loads the
extension Performance Monitor DLLs, including snaperf.dll), the following
errors may occur:
- All Performance Monitor objects and counters are blank, even SNA Server
ones. When you start Performance Monitor under a debugger, it indicates
that the Performance Monitor heap is corrupted. This causes Performance
Monitor (Perfmon.exe) to encounter an access violation (0xC0000005).
- When you start Performance Monitor on another system, focus on the
computer running SNA Server 4.0, and press the "+" key, an access
violation (0xC0000005) occurs in Winlogon.exe, leading to a STOP
0xC000021A.
- The following log entry may appear in the <ntroot>\drwtsn32.log file:
Application exception occurred:
App: exe\winlogon.dbg (<process ID>)
Exception number: c0000005 (access violation)
[...]
function: RtlAllocateHeap
[...]
NOTE: A similar access violation problem may occur with SNA Server 3.0,
though this problem is fixed when applying 3.0 Service Pack 2.
CAUSE
This problem is caused by a regression introduced in SNA Server 4.0 when
support for multiple instances of the SNA Server service on a single
computer was added. However, multiple SNA Server services do not need to be
configured in order to encounter this problem.
WORKAROUND
Do not run Windows NT Performance Monitor against SNA Server.
STATUS
Microsoft has confirmed this to be a problem in SNA Server version 4.0.
This problem was corrected in the latest SNA Server version 4.0 U.S.
Service Pack. For information on obtaining this Service Pack, query on
the following word in the Microsoft Knowledge Base (without the spaces):
| Modification Type: | Minor | Last Reviewed: | 9/22/2005 |
|---|
| Keywords: | kbHotfixServer kbQFE kbbug kbfix KB180054 |
|---|
|