The StackHash scripting feature relies on running cdb.exe from a Windows service (the StackHash Service).
When running in a service cdb.exe uses WinHttp to download any symbols required during analysis. If a WinHttp proxy is specified cdb.exe will use this to connect to the Internet. If your computer does not have a WinHttp proxy configured then cdb.exe will default to using a dummy proxy server. This allows symbols to be downloaded from local hosts but effectively blocks Internet access including to the Microsoft public symbol server.
This behavior can be overridden by setting a registry value:
Key: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Symbol Server DWORD (32-bit) Value: NoInternetProxy=1
On 64-bit systems the following value should also be set for 32-bit applications:
Key: HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Symbol Server DWORD (32-bit) Value: NoInternetProxy=1
The StackHash installer will set both keys if you do not have a WinHttp proxy configured. If your configuration changes then you may need to manually add or remove these keys.
You can view and change your WinHttp proxy using the netsh command:
netsh winhttp -?
Note that WinHttp proxy settings are separate from other proxy settings (i.e. Internet Explorer).