TN3270 Server Access Violation in Mngext!MngDeleteObject() (245453)

SYMPTOMS

The SNA Server TN3270 Server process (Tn3servr.exe) may fail unexpectedly with an access violation in routine mngext!MngDeleteObject. If Drwtsn32.exe is configured as the default debugger, a Drwtsn32.log file will be created and will include the following failure information:

Application exception occurred:
        App: exe\tn3servr.dbg (pid=process id)
        When: (date and time)
        Exception number: c0000005 (access violation)

[...]

State Dump for Thread Id (thread)

eax=00000000 ebx=00000000 ecx=00000000 edx=0ca40440 esi=0c9fff98 edi=00243160
eip=60a01dd7 esp=0c9fff78 ebp=77f67500 iopl=0         nv up ei pl zr na po nc
cs=001b  ss=0023  ds=0023  es=0023  fs=0038  gs=0000             efl=00000246

function: MngDeleteObject
        60a01db8 59               pop     ecx
        60a01db9 c20800           ret     0x8
        60a01dbc 6a00             push    0x0
        60a01dbe 8d44240c         lea     eax,[esp+0xc]
        60a01dc2 6a00             push    0x0
        60a01dc4 50               push    eax
        60a01dc5 8bcf             mov     ecx,edi
        60a01dc7 c70600000000     mov     dword ptr [esi],0x0
        60a01dcd ff15d010a060 
                   call    dword ptr [_imp_?GetNotify (60a010d0)]
        60a01dd3 8b4c2408         mov     ecx,[esp+0x8]          
FAULT ->60a01dd7 8b11             mov     edx,[ecx] 
        60a01dd9 ff5220           call    dword ptr [edx+0x20]   
        60a01ddc 5f               pop     edi
        60a01ddd 5e               pop     esi
        60a01dde 59               pop     ecx
        60a01ddf c20800           ret     0x8

*---- Stack Back Trace ----*

FramePtr ReturnAd Param#1  Param#2  Param#3  Param#4  Function Name
77f67500 8b000000 83042454 7500147a 42ff904f 8b197504 mngext!MngDeleteObject