SNA Server Fails With Access Violation in S1pnsuns()

SYMPTOMS

The SNA Server service may fail unexpectedly with an access violation, causing all users to lose their SNA sessions. When this specific problem occurs, SNA Server will log the following event:

   Source: SNA Server
   Event: 624
   Creating dump file SNADUMP.LOG for snaservr.exe
				

If Drwtsn32.exe is the default debugger, the Drwtsn32.log file will indicate an access violation fault in routine s1pnsuns(). The log entry will appear as follows:

   Application exception occurred:

           App: snaservr.DBG (pid=164)
           <date, time omitted>
           Exception number: c0000005 (access violation)

   [...]

   State Dump for Thread Id 0xa5

   eax=00000000 ebx=0000009a ecx=00000000 edx=00420000 esi=01281aec
   edi=00000000
   eip=003e1389 esp=002bfdd4 ebp=0000002f iopl=0         nv up ei pl nz na
   po nc
   cs=001b  ss=0023  ds=0023  es=0023  fs=0038  gs=0000  efl=00000206   function: s1pnsuns

           003e1351 662d0102         sub     ax,0x201
           003e1355 0fbfc8           movsx   ecx,ax
           003e1358 6689842480000000 mov     [esp+0x80],ax   ss:002bfe54=0711
           003e1360 8b048d80694600 mov eax,[s1scb (00466980)+ecx*4]
                           ds:00000000=????????
           003e1367 66c74424127900   mov     word ptr [esp+0x12],0x79
                           ss:0089e6f8=????
           003e136e 668b9092000000   mov     dx,[eax+0x92]   ds:00000092=????
           003e1375 6689542418       mov     [esp+0x18],dx   ss:0089e6f8=????
           003e137a 0fbf480a         movsx   ecx,word ptr [eax+0xa]
                           ds:005de923=0000
           003e137e 66bb9a00         mov     bx,0x9a
           003e1382 8b048dcce84400          ds:00000000=????????
                                     mov     eax,[s1dfttmo+0x6
                          (0044e8cc)+ecx*4]
   FAULT ->003e1389 668b403e         mov     ax,[eax+0x3e]