I'm attempting debugging on a production server using sos to try and find
the root cause of a NullReferenceException. I've broken to process in the
debugger and used the commands

!load clr10/sos.dll
sxe av ( NullReferenceException is handled as an access violation )

Then used !u @eip to find out the failing line in the .NET function which
throws. The output is shown below. Previously when debugging we've sound
very good symbolic information here for .NET calls made in the
SupplierPayment.CreateFromXml function however on the production server
there is very little information which makes much sense.

Any ideas why? Debugging symbols aren't usually required for the components
because the .NET meta data which sos reads is usually fine.


0:000> !u @eip
Will print '>>> ' at address: 0x03794fb5
Normal JIT generated code
[DEFAULT] Class Tranmit.Sprinter.Invoicing.Interfaces.ISupplierPay ment
Tranmit.Sprinter.Invoicing.SupplierPayment.CreateF romXml(Class
System.Xml.XmlNode,Class System.Collections.Hashtable,Boolean)
Begin 0x03794ed8, size 0xf4
03794ed8 50 push eax
03794ed9 57 push edi
03794eda 56 push esi
03794edb 53 push ebx
03794edc 55 push ebp
03794edd 8bf9 mov edi,ecx
03794edf 8bea mov ebp,edx
03794ee1 33f6 xor esi,esi
03794ee3 8b1534a01802 mov edx,[0218a034] ("TransactionType")
03794ee9 8bcf mov ecx,edi
03794eeb 3909 cmp [ecx],ecx
*** WARNING: Unable to verify checksum for
c:\windows\assembly\nativeimages1_v1.1.4322\system .xml\1.0.5000.0__b77a5c561934e089_3fa3f30d\system. xml.dll
*** ERROR: Module load completed but symbols could not be loaded for
c:\windows\assembly\nativeimages1_v1.1.4322\system .xml\1.0.5000.0__b77a5c561934e089_3fa3f30d\system. xml.dll
03794eed e886be6278 call system_xml_7bd60000+0x60d78 (7bdc0d78)
(System.Xml.XmlNode.SelectSingleNode)
03794ef2 8bd8 mov ebx,eax
03794ef4 85db test ebx,ebx
03794ef6 0f84b4000000 je 03794fb0
03794efc b930c11601 mov ecx,0x116c130 (MT:
Tranmit.Sprinter.Invoicing.Interfaces.PaymentTrans actionType)
03794f01 e892a6a975 call mscorwks!CorExitProcess+0x19b4d (7922f598)
(mscorwks!CorExitProcess)
03794f06 89442410 mov [esp+0x10],eax
03794f0a 8bcb mov ecx,ebx
03794f0c 8b01 mov eax,[ecx]
03794f0e ff90d4000000 call dword ptr [eax+0xd4]
03794f14 6a01 push 0x1
03794f16 8b4c2414 mov ecx,[esp+0x14]
03794f1a 8bd0 mov edx,eax
*** WARNING: Unable to verify checksum for
c:\windows\assembly\nativeimages1_v1.1.4322\mscorl ib\1.0.5000.0__b77a5c561934e089_92e82560\mscorlib. dll
*** ERROR: Module load completed but symbols could not be loaded for
c:\windows\assembly\nativeimages1_v1.1.4322\mscorl ib\1.0.5000.0__b77a5c561934e089_92e82560\mscorlib. dll
03794f1c e8ef682076 call mscorlib_79990000+0xb810 (7999b810)
(System.Enum.Parse)
03794f21 8bd8 mov ebx,eax
03794f23 813b30c11601 cmp dword ptr [ebx],0x116c130
03794f29 740c jz 03794f37
03794f2b 8bd3 mov edx,ebx
03794f2d b930c11601 mov ecx,0x116c130 (MT:
Tranmit.Sprinter.Invoicing.Interfaces.PaymentTrans actionType)
03794f32 e811b7a575 call mscorwks!Ordinal17+0x1b958 (791f0648)
(mscorwks!Ordinal17)
03794f37 83c304 add ebx,0x4
03794f3a 8b03 mov eax,[ebx]
03794f3c 83f802 cmp eax,0x2
03794f3f 736f jnb 03794fb0
03794f41 ff2485d04f7903 jmp dword ptr [03794fd0+eax*4]
03794f48 b9f4c61601 mov ecx,0x116c6f4 (MT:
Tranmit.Sprinter.Invoicing.SupplierInvoice)
03794f4d e8c6d029fd call 00a32018mscorwks.pdb not exist
Use alternate method which may not work.

03794f52 8bf0 mov esi,eax
03794f54 c7461400000000 mov dword ptr [esi+0x14],0x0
03794f5b 8bce mov ecx,esi
03794f5d 8b01 mov eax,[ecx]
03794f5f ff5038 call dword ptr [eax+0x38]
03794f62 c6465800 mov byte ptr [esi+0x58],0x0
03794f66 8bce mov ecx,esi
03794f68 8b01 mov eax,[ecx]
03794f6a ff5038 call dword ptr [eax+0x38]
03794f6d 8bd6 mov edx,esi
03794f6f b9a0b51601 mov ecx,0x116b5a0 (MT:
Tranmit.Sprinter.Invoicing.SupplierPayment)
03794f74 e866aca975 call mscorwks!CorExitProcess+0x1a194 (7922fbdf)
(mscorwks!CorExitProcess)
03794f79 8bf0 mov esi,eax
03794f7b eb33 jmp 03794fb0
03794f7d b92cc31601 mov ecx,0x116c32c (MT:
Tranmit.Sprinter.Invoicing.CreditNote)
03794f82 e891d029fd call 00a32018mscorwks.pdb not exist
Use alternate method which may not work.

03794f87 8bf0 mov esi,eax
03794f89 c7461400000000 mov dword ptr [esi+0x14],0x0
03794f90 8bce mov ecx,esi
03794f92 8b01 mov eax,[ecx]
03794f94 ff5038 call dword ptr [eax+0x38]
03794f97 c6465800 mov byte ptr [esi+0x58],0x0
03794f9b 8bce mov ecx,esi
03794f9d 8b01 mov eax,[ecx]
03794f9f ff5038 call dword ptr [eax+0x38]
03794fa2 8bd6 mov edx,esi
03794fa4 b9a0b51601 mov ecx,0x116b5a0 (MT:
Tranmit.Sprinter.Invoicing.SupplierPayment)
03794fa9 e831aca975 call mscorwks!CorExitProcess+0x1a194 (7922fbdf)
(mscorwks!CorExitProcess)
03794fae 8bf0 mov esi,eax
03794fb0 55 push ebp
03794fb1 8bd7 mov edx,edi
03794fb3 8bce mov ecx,esi
03794fba 8b8070010000 mov eax,[eax+0x170]
03794fc0 ff10 call dword ptr [eax]
03794fc2 8bc6 mov eax,esi
03794fc4 5d pop ebp
03794fc5 5b pop ebx
03794fc6 5e pop esi
03794fc7 5f pop edi
03794fc8 59 pop ecx
03794fc9 c20400 ret 0x4