.NET Questions and Solutions

Symptoms
An application exception (trap) may occur on the SNA Server computer when you use the Rumba 5.2 TN5250 client to connect to the TN5250 Service. If you have Dr. Watson (Drwtsn32.exe) configured as the default debugger, a Drwtsn32.log file is created in the [NTROOT] directory. The following events are created in the Application event log of the Event Viewer:

Event ID: 5
Source : SNA TN5250 ServerDescription:
The SNA TN5250 Service detected an internal error.
File = ..\shared\tn5tnspm.c
Line = 3477
Fail = ((NB_IPS *)dsi5_data)->buf_size >= ((NB_IPS *)dsi5_data)->ips_length
Parm = 0×0
Event ID: 4097
Source: DrWatson
The application, exe\tn5250.dbg, generated an application error The error occurred on1/25/2000 @ 20:58: 3.406.
The exception generated was 80000003 at address 77f76274 (DbgBreakPoint).The following is an example of the exception in DbgBreakPoint:

Application exception occurred:App: exe\tn5250.dbg (pid=326)When: 1/25/2000 @ 20:58:3.406Exception number: 80000003 (hardcoded breakpoint)function: DbgBreakPointFAULT ->77f76274 ccint377f76275 c3ret77f76276 8bc0moveax,eax
Resolution
To resolve this problem, obtain the latest service pack for SNA Server 4.0. For additional information, click the following article number to view the article in theMicrosoft Knowledge Base:
215838?(http://support.microsoft.com/kb/215838/EN-US/) How to Obtain the Latest SNA Server Version 4.0 Service Pack

Symptoms
When you try to run a program, the following Dr. Watson error message may be displayed:

An application error has occurred and an application error log is being generated.
<Program.exe>
Exception: hardcoded-breakpoint (0×80000003), Address: 0×77f76274Where <Program.exe> is the name of your program’s executable file. The Address value may be different.
Resolution
This problem occurs if a program makes a request for memory with the MEM_TOP_DOWN flag set. A bad pointer may be returned, causing the Dr. Watson error message.

Symptoms
An application exception (trap) occurs in the SNA Server service(SNASERVR.EXE) when used with the Attachmate Extra! 3270 version 4.xemulator.
If you have Dr. Watson (DRWTSN32.EXE) configured as the default debugger,the DRWTSN32.LOG shows an exception similar to the following:

Application exception occurred:
App: snaservr.DBG (pid=147)
When: 8/1/1995 @ 16:39:1.590
Exception number: c0000005 (access violation)In addition, SNA Server logs Event 624 in the Windows NT Application Log(as seen in the Event Viewer) when this trap occurs. The following is adetailed description of the Event 624 that is logged when this trap occurs:

Creating dump file C:\SNA\TRACES\SNADUMP.LOG for SNASERVR.EXE
EXPLANATION
A process (SNASERVR.EXE) ended abnormally due to a protection
violation or similar condition and a dump file SNADUMP.LOG has been
created that contains information about the state of the process at
the time of the exception. Register information is contained in your
Windows NT root directory in the file DRWTSN32.LOG.
Resolution
A 3270 emulator has two connections to the SNA Server service. Oneconnection is for SSCP-LU data and the other one is for PLU-SLU (PrimaryLogical Unit – Secondary Logical Unit) data. The SNA Server service trap iscaused because the 3270 emulator is sending a PLU-SLU message on theconnection that is only meant to handle SSCP-LU data. This is behaviorwhich the SNA Server service is not expecting, and it traps when itaccesses its session control block for the SSCP-LU session and treats it asa control block for the PLU-SLU session.

Symptoms
The SNA Server stops responding (hangs) and Appletalk client computers areunable to attain session connections. In the Event Viewer, the followingapplication events appear:

Event ID: 624
Source: SNADUMP.LOG
Description: A process SNABASE.EXE ended abnormally due to a protectionviolation, or similar condition.
Event ID: 4097
Source: Dr. Watson Log
This application, SNABASE.DBG generated an applicaiton error. The error
occurred on <date>. The exception generated was C0000005 at address <address>.A portion of the DRWTSN32.LOG file states the following:

App: snabase.DBG (pid=160)When: <date> @ <time>Exception number: c0000005 (access violation) NOTE: Your DRWTSN32.LOG file will appear somewhat different than thisexample.
Resolution
The SNAAT.DLL send routine is not checking to see if the L-Table is alreadyin a closing state. Therefore, it tries to access its pending queue, whichhas been released. This causes the application exception in SNABASE.EXE.

Symptoms
If the SnaNetMn service is configured for automatic startup in ControlPanel/Services or if it is started manually, the following popup errormessage is displayed:

SNA Server – ERROR # 03…OK Note: This message will not appear in the application event log.
In addition, an application exception in Snanmvt.exe occurs that generatesa Dr. Watson log in the Windows NT directory. The entry created in theDrwtsn32.log file will be similar to the following:

Application exception occurred:App: exe\snanmvt.dbg (pid=<pid #>)When: <date> @ <time>Exception number: c0000005 (access violation)function: sepdnmsd_int[...]FAULT ->67241535 803a00cmpbyte ptr [edx],0×0[...] The following messages will be logged in the Windows NT Application Eventlog:

Event ID: 4097Source: DrWatsonDescription: The application, exe\snanmvt.dbg, generated an applicationerror. The error occurred on<date> @<time>. The exception generatedwas c0000005 at address 67241535 (sepdnmsd_int)Event ID: 624Source: SNA ServerDescription: Creating dump file <snaroot>\traces\snadump.log forsnanmvt.exe
Resolution
The application exception occurs because a corrupted buffer caused stackcorruption while attempting to display popup errors that contained longerror messages. The error message that results from starting the SnaNetMnservice contains a long description, which is why the application exceptionoccurs.
Note: Other errors may result in an application exception when a popuperror message is being displayed. These application exceptions may bereported against components other than Snanmvt.exe.

Symptoms
When you are running an Advanced Program-to-Program Communications (APPC) or Common Programming Interface for Communications (CPI-C) application, you may encounter an Access Violation (AV) in DMODInitReceiveAllocate.
If Dr. Watson is configured as the default debugger, an entry similar to the following may be appended to the Drwtsn32.log file:

function: DMODInitReceiveAlloc6721a1c4 8d54d034leaedx,[eax+edx*8+0x34]ds:040cbeef=????????6721a1c8 83c9fforecx,0xff6721a1cb 33c0xoreax,eax6721a1cd f2aerepnescasbes:02ced4e8=??6721a1cf f7d1notecx6721a1d1 2bf9subedi,ecx6721a1d3 8bc1moveax,ecx6721a1d5 8bf7movesi,edi6721a1d7 8bfamovedi,edx6721a1d9 c1e902shrecx,0×2FAULT ->6721a1dc f3a5repmovsd ds:0284f79c=20202020 es:02ced4e8=????????6721a1de 8bc8movecx,eax6721a1e0 83e103andecx,0×36721a1e3 f3a4repmovsbds:0284f79c=20 es:02ced4e8=??6721a1e5 33c0xoreax,eax6721a1e7 8b7dc4movedi,[ebp-0x3c]ss:03c2e26e=????????6721a1ea 668b4704movax,[edi+0x4]ds:040cbeef=????6721a1ee 8d0c40leaecx,[eax+eax*2]ds:0000001b=????????6721a1f1 c1e103shlecx,0×36721a1f4 2bc8subecx,eax6721a1f6 8bb548ffffffmovesi,[ebp+0xffffff48]ss:0284f7b0=02cc025c6721a1fc c744ce1004000000ds:013dea0d=????????movdword ptr [esi+ecx*8+0x10],0×4*—-> Stack Back Trace <—-*FramePtr ReturnAd Param#1Param#2Param#3Param#4Function Name0284f868 63404de3 62e1b5b0 00000001 00a9a4bc 00a9a4d8 snadmod!DMODInitReceiveAlloc (FPO: Non-FPO [5,128,3])0284f89c 63403254 00000000 63401bb6 0284fa0c 0f7e0000 wappc32!receive_allocate_proc(FPO: [EBP 0x00014000] [0,3,4])0284f8a4 63401bb6 0284fa0c 0f7e0000 00000000 77f674c0 wappc32!ps_verb_router(FPO: [0,0,1])0284f9bc 63401737 0f7e0000 00000002 62e018a0 00000000 wappc32!Appc_Main(FPO: [EBP 0x0284fa0c] [4,65,4])
Resolution
The application exception is caused by a buffer overrun during Dynamic Load processing.