Symbols for "ntdll.dll" could not be downloaded from Microsoft Symbol Servers

Question

I am trying to port my Windows Phone 8 app to Windows 10. I am able to build my app. When I try to deploy my app in Release x86 on a Mobile emulator, it fails & gives the following msg:

Symbols for ntdll.dll could not be downloaded from Microsoft Symbol Servers. Exception string and call stacks may not work correctly. Make sure you have network connection and try again

Even though I am trying to run my app in Release mode, I am not sure why VS-2015 is tyring to download these debugging symbols.
After a bit of searching on the internet, I have done these, yet I continue to see the issue:

• I have already downloaded, all necessary symbols available from Windows-10 from here: https://msdn.microsoft.com/en-us/windows/hardware/gg463028.aspx to C:\Symbols
• In VS Tools->Options->Debugging->Server, I have created two entries for Symbol file).pdb) locations. One points to Microsoft Symbol Servers and the other to C:\Symbols
• The machine has internet connection, so there is no problem with the connection as the error message points to.
• I have set environment var _NT_SYMBOL_PATH to SRVc:\symbolshttp://msdl.microsoft.com/download/symbols

Has anyone faced this issue?

Answer 1

this is a known issue with the x86 NTDLL.dll in Version 10.0.10586.122 (th2_release_inmarket.160222-1549). The file is missing on the Microsoft symbol server:

SYMSRV:  Successfully closed the connection to the Server.
SYMSRV:  d:\sym\dl\wn\wntdll.pdb\39814CFBD1A74710A3F8FCAD3D7EC5661\wntdll.pdb not found
SYMSRV:  https://msdl.microsoft.com/download/symbols/wntdll.pdb/39814CFBD1A74710A3F8FCAD3D7EC5661/wntdll.pdb not found
DBGHELP: wntdll.pdb - file not found
*** ERROR: Symbol file could not be found.  Defaulted to export symbols for ntdll.dll - 

I've already reported it to Microsoft and they investigate the issue.

// Update 2016-03-15

The wntdll.pdb is now available on the symbol server:

0:000> lmvm ntdll
Browse full module list
start    end        module name
77a70000 77beb000   ntdll      (pdb symbols)   

d:\sym\dl\wn\wntdll.pdb\39814CFBD1A74710A3F8FCAD3D7EC5661\wntdll.pdb


    Loaded symbol image file: ntdll.dll
    Image path: C:\Windows\System32\ntdll.dll
    Image name: ntdll.dll
    Browse all global symbols  functions  data
    Timestamp:        Tue Feb 23 09:23:17 2016 (56CC16F5)
    CheckSum:         001873F8
    ImageSize:        0017B000
    File version:     10.0.10586.122
    Product version:  10.0.10586.122
    File flags:       0 (Mask 3F)
    File OS:          40004 NT Win32
    File type:        2.0 Dll
    File date:        00000000.00000000
    Translations:     0409.04b0
    CompanyName:      Microsoft Corporation
    ProductName:      Microsoft® Windows® Operating System
    InternalName:     ntdll.dll
    OriginalFilename: ntdll.dll
    ProductVersion:   10.0.10586.122
    FileVersion:      10.0.10586.122 (th2_release_inmarket.160222-1549)
    FileDescription:  NT Layer DLL
    LegalCopyright:   © Microsoft Corporation. All rights reserved.