WinDBG doesn't display source lines despite loading private pdb files


I am trying to debug a problem in a native DLL using WinDBG. I believe that I have the private symbols loaded, but WinDBG is not displaying the source lines or parameter information. Here is what I am observing; any help would be greatly appreciated!

I have the PDB which I believe corresponds to the DLL in the symbol search path. Running lm I see:

01050000 01058000   3NMSMTHR C (private pdb symbols)  e:\ads_symbols\3NMSMTHR.pdb

As this states "private pdb symbols" I expect that this is the private pdb.

I also ran symchk and see the following output:

C:\utils\inetmgr\patch01>"c:\Program Files\Debugging Tools for Windows (x86)\symchk.exe" /v 3nmsmthr.dll /s c:\utils\inetmgr\patch01
[SYMCHK] Searching for symbols to C:\utils\inetmgr\patch01\3nmsmthr.dll in path c:\utils\inetmgr\patch01
DBGHELP: Symbol Search Path: c:\utils\inetmgr\patch01
[SYMCHK] Using search path "c:\utils\inetmgr\patch01"
DBGHELP: No header for C:\utils\inetmgr\patch01\3NMSMTHR.DLL.  Searching for image on disk
DBGHELP: C:\utils\inetmgr\patch01\3NMSMTHR.DLL - OK
DBGHELP: 3NMSMTHR - private symbols & lines
[SYMCHK] MODULE64 Info ----------------------
[SYMCHK] Struct size: 1680 bytes
[SYMCHK] Base: 0x10000000
[SYMCHK] Image size: 32768 bytes
[SYMCHK] Date: 0x4cc1b0f8
[SYMCHK] Checksum: 0x00000000
[SYMCHK] NumSyms: 0
[SYMCHK] SymType: SymPDB
[SYMCHK] ImageName: C:\utils\inetmgr\patch01\3NMSMTHR.DLL
[SYMCHK] LoadedImage: C:\utils\inetmgr\patch01\3NMSMTHR.DLL
[SYMCHK] PDB: "c:\utils\inetmgr\patch01\3NMSMTHR.pdb"
[SYMCHK] CV DWORD: 0x53445352
[SYMCHK] CV Data:  I:\usr\bpi\adrutl\3NMSMTHR.pdb
[SYMCHK] PDB Sig:  0
[SYMCHK] PDB7 Sig: {A865C40A-5070-4752-AD1F-CD3087843807}
[SYMCHK] Age: 4
[SYMCHK] Line nubmers: TRUE
[SYMCHK] Global syms:  TRUE
[SYMCHK] Type Info:    TRUE
[SYMCHK] ------------------------------------
SymbolCheckVersion  0x00000002
Result              0x001f0001
DbgTimeDateStamp    0x4cc1b0f8
DbgSizeOfImage      0x00008000
DbgChecksum         0x00000000
PdbFilename         c:\utils\inetmgr\patch01\3NMSMTHR.pdb
PdbSignature        {A865C40A-5070-4752-AD1F-CD3087843807}
PdbDbiAge           0x00000004
[SYMCHK] [ 0x00000000 - 0x001f0001 ] Checked "C:\utils\inetmgr\patch01\3NMSMTHR.DLL"

SYMCHK: FAILED files = 0

This finds the PDB in the right path I've given it (note that I copied this exact PDB file to e:\ads_symbols which is the path seen in the lm output). This symchk output states Line Numbers: true and thus I expect to see private style information. However, if I run ~kv then for my functions in the stack trace I see:

00bef2ac 01052a8a 00000000 00000000 00020aa4 3NMSMTHR!BPMThrProcTerm+0x2c0
00bef2cc 100073eb 00bef4d8 00000000 00000000 3NMSMTHR!BPMThrThreadInitName+0x2a

And this doesn't seem like its reading the private information-- I don't get the source listing like I do for the MS CRT functions which have private symbols on the MSFT symbol server. Also if I do x /t /d 3NMSMTHR!ThreadInitName then I get

01052a60 <NoType> 3NMSMTHR!BPMThrThreadInitName = <no type information>

And lastly if I try to use .frame3 (to go to that frame) and then execute dv to display the locals, I receive the:

0:001> .frame
03 00bef2cc 100073eb 3NMSMTHR!BPMThrThreadInitName+0x2a
0:001> dv
Unable to enumerate locals, HRESULT 0x80004005
Private symbols (symbols.pri) are required for locals.
Type ".hh dbgerr005" for details.

This doesn't make sense to me. Any help would be much appreciated. My overall goal is to get the parameter and source information. OR to confirm that the PDB file I have is in fact NOT the private symbols. I didn't build this DLL or PDB nor do I know any specifics about the linker options passed to it.



I failed to mention that I am getting the checksum error:

*** WARNING: Unable to verify checksum for C:\utils\inetmgr\3NMSMTHR.dll

Sorry! I was trying to run the .lines command as suggested below and I see:

*** WARNING: Unable to verify checksum for C:\utils\inetmgr\3NMSMTHR.dll
DBGHELP: 3NMSMTHR - private symbols & lines 
Line number information will not be loaded

So I guess that's my problem. Which leads to my next question: is there a way to fix the checksum (which is listed as 0, see above symchk output)? This PDB is the correct one given the symchk output. Can I have it bypass the checksum check?


For anyone else that comes across this: I was able to fix the checksum warning by:

editbin /release 3NMSMTHR.DLL

This set the checksum in the PE header. Then I had to run the


In WinDbg in order to force it to load the PDB even though the timestamp on the DLL was different. I'm sure that alternatively I could've used some utility to update the modified timestamp as well.

That fixed the warning about the checksum...but STILL no parameter info (running dv on the right frame), no source line info, etc.

So now I'm lost. Is it possible that these PDBs don't contain that info? How could I confirm that? How would I build them to contain it? We use NMAKE to build these.


I rebuilt the DLL and PDB as DEBUG and then got all of the stack trace information that I expected. So now my question is: (1) is it possible to build in release and get the static functions, parameter info, etc. (private symbol info)? and (2) the stack trace I was getting with the release dlls+pdbs was incorrect-- the first function entrypoint was correct, but then the next stack frame showed a func that wasn't called. My assumption is that the release DLL inlined some functions and somehow the PDB was just "guessing" at the function in that frame? Very strange.

asked on Stack Overflow May 21, 2011 by steve_ash • edited May 23, 2011 by steve_ash

4 Answers


Did you try the .lines command?

answered on Stack Overflow May 21, 2011 by Naveen

You will not have type information if the function is written in assembly language. Also it is possible that a static library was linked to the DLL and the static library did not have full debug information.

answered on Stack Overflow May 21, 2011 by John

If you want to be able to make sense of dumps or stack traces even in Release mode, you should ensure the following:

  1. You compile with /Zi or /ZI (Debug Information Format is one of the two Program Database options).
  2. You do not compile with /Oy (Omit Frame Pointers).
  3. You link with /DEBUG (Generate Debug Info).
  4. You keep (but don't distribute) the resulting .pdb file.

The main thing is to avoid omitting frame pointers; omitting them saves a little bit of time/space in a function call but makes it very hard to stack walk. Note that you may still get odd stack traces from release builds due to other optimisation settings (particularly inlining) but they should still have the majority of interesting functions.

answered on Stack Overflow Jul 3, 2012 by Miral

I know this is old, but for anyone coming across this issue, what worked for me was to run ".lines -e". This is probably what Naveen was suggesting.

answered on Stack Overflow May 2, 2018 by Mihai

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