windbg - module not loading "dll not found in the image list" - .net-4.0

Question

I am trying to get a proper callstack for an unhandled exception in my VS2010 .net4 application using windbg.
The main program is a console application. This dll loads with it's symbols properly.
In the same directory, I have a dll+matching pdb which won't load.
I am running the app on a windows server 2008 R2, 64 bit (no VS installed). But the app was compiled on 32bit. I am using the winX86 debugger to attach to the process.
I have downloaded sosex that supports .net 4 from
http://www.stevestechspot.com/ (the 32 bit version)
the sos.dll (from "C:\Program Files (x86)\Debugging Tools for Windows (x86)\clr10\sos.dll") version is 6.12.2.633.
Issued the following commands:
sympath+ "...folder of exe and dll"
.loadby sos clr
.load sosex.dll
When running !mk I get the following:
Thread 0:
ESP EIP
00:U 0016ec6c 5f636578 0x5f636578
01:U 0016ec70 05f1380f SN!SN_MedistoreEngine::FetchNotes+0x13f [v:\mp\mp\src\sn\sn_medistoreengine.cpp # 59]
02:M 0016edbc 07dd0db1 SN_Bridge.SNB_bridge.fetch_notes(IOD_Msg*, System.String, System.String, Boolean)(+0x4a IL)(+0x131 Native) [v:\mp\portal\commonutils\src\snb\snb_bridge.cpp, # 142,0]
03:M 0016ef24 055bfde5 SN_Bridge.SNB_bridge.FetchNotesByStudyUId(System.String, System.String, System.Collections.Generic.List`1<SN_Bridge.SNB_StickyNote>)(+0x25 IL)(+0x55 Native) [v:\mp\portal\commonutils\src\snb\snb_bridge.cpp, # 296,0]
04:M 0016efb0 055bfd22
"xxx.Services.StickyNotes.dll" was not found in the image list.
Debugger will attempt to load "xxx.Services.StickyNotes.dll" at given base 00000000.
Please provide the full image name, including the extension (i.e. kernel32.dll)
for more reliable results.Base address and size overrides can be given as
.reload <image.ext>=<base>,<size>.
Unable to add module at 00000000
"xxx.ni.Services.StickyNotes.dll" was not found in the image list.
Debugger will attempt to load "xxx.ni.Services.StickyNotes.dll" at given base 00000000.
Please provide the full image name, including the extension (i.e. kernel32.dll)
for more reliable results.Base address and size overrides can be given as
.reload <image.ext>=<base>,<size>.
Unable to add module at 00000000
xxx.Services.StickyNotes.StickyNotesLogic.StickyNotesByStudyID(System.String, System.String, System.String)(+0x1d IL)(+0x52 Native)
05:M 0016efcc 055ba0ab SNConsole.Program.Main(System.String[])(+0x101 IL)(+0x24b Native) [D:\Documents and Settings\tamar\My Documents\Visual Studio 2010\Projects\SNConsole\Program.cs, # 48,17]
06:U 0016f02c 72da21db clr+0x21db
07:U 0016f034 72dae021 clr!DllUnregisterServerInternal+0x8025
08:U 0016f090 72dbc58d clr!DllUnregisterServerInternal+0x16591
When running !clrstack I get the following:
PDB symbol for clr.dll not loaded
OS Thread Id: 0x2984 (0)
Child SP IP Call Site
0016edc8 5f636578 [InlinedCallFrame: 0016edc8]
0016edc4 07dd0db1 SN_Bridge.SNB_bridge.fetch_notes(IOD_Msg*, System.String, System.String, Boolean) [v:\mp\portal\commonutils\src\snb\snb_bridge.cpp # 142]
0016ef30 055bfde5 SN_Bridge.SNB_bridge.FetchNotesByStudyUId(System.String, System.String, System.Collections.Generic.List`1<SN_Bridge.SNB_StickyNote>) [v:\mp\portal\commonutils\src\snb\snb_bridge.cpp # 296]
0016efb0 055bfd22 xxx.Services.StickyNotes.StickyNotesLogic.StickyNotesByStudyID(System.String, System.String, System.String)
0016efcc 055ba0ab SNConsole.Program.Main(System.String[]) [D:\Documents and Settings\tamar\My Documents\Visual Studio 2010\Projects\SNConsole\Program.cs # 48]
0016f25c 72da21db [GCFrame: 0016f25c]
As you can see, in both cases I get the file name + row number in the stack, except for the xxx.Services.StickyNotes.dll line.
I've tried:
.realod /f ""c:...\xxx.Services.StickyNotes.dll" - same errors
and
ld "c:...\xxx.Services.StickyNotes.dll" which resulted in
No modules matched
'c:...\Bin\xxx.Services.StickyNotes.dll'
using !sym noisy didn't help, I think it doesn't even try to load the pdb since the module itself isn't loaded.
I can't figure out why this specific dll won't load. SN_Console.exe and SNB_Bridge.dll load without a problem from the same directory.
(I am not concerned with the exception itself, I planted the code that creates is. The issue is about setting up a good debugging environment).
Thanks in advance,
Tamar

Answer 1

I happened to answer this question in person, but here's the documented story in case anyone else stumbles upon it: http://blogs.microsoft.co.il/blogs/sasha/archive/2011/01/16/clr-4-does-not-use-loadlibrary-to-load-assemblies.aspx
The big picture is that CLR 4 doesn't use LoadLibrary to load assemblies, so the debugger can't pick up the DLL and therefore its symbols.

Answer 2

You can hint the debugger the location of the DLL in its address space using:
.reload /f "c:...\xxx.Services.StickyNotes.dll=image_base_address"
image_base_address is the start of the address range which this DLL is mapped in the process. You can find this value in the DLL Pane of Process Explorer.
I wrote about it with a little more detail here.