Problem with Web Service Parameter

Question

I am having a problem with a simple web service that accepts a parameter. For example:
[WebMethod]
public string HelloWorld(string strParam)
{ return "Hi"; }
This method returns a 500 Internal Server Error. When I remove the parameter:
[WebMethod]
public string HelloWorld()
{ return "Hi"; }
the web service works fine. Does anyone have any experience with this or know of a direction to log what is causing the error (nothing is in the event log).
Thanks.

ctcoley · Answer

I have resolved this issue. It was not a direct problem with the web service or the .Net Framework, but an odd combination of VPN and IIS. For whatever reason, when I select both Windows Integrated and Anonymous, the web service works from an external resource (via vpn). However, when only Anonymous is checked, the web service would fail. This only related to external requests through the vpn. From internal request, the web service worked the same regardless of the Windows Integrated option.