Error: %1 is not a valid Win32 application when trying to call wind32 dll from ASP.NET on IIS7 RRS feed

  • Question

  • User-928055762 posted

    I have a Silverlight+Asp.Net application that is working properly on IIS7, Windows Server 2008R2.

    In one of my request I I'm trying to load win32 dll in the ASP.NET application on IIS 7, OS Windows Server 2008R2, but it throws "%1 is not a valid Win32 application".

    The application is loading the dll and works properly on my dev machine and Visual Studio 2012 development server, Winodws 8 64bit.

    I've read for problems with 32bit applications on 64bit os and iis, but in most cases the web applications were not working at all. However as my dll is 32 bit I set "Enable 32-Bit Applications"=true on the application pool and error is NOT thrown but nothing happens. When execution is trying to load the dll, the application is not responding and timeout is exceeded.

    Any ideas of how to get win32 dll working ?

    Thursday, February 7, 2013 8:50 AM


  • User-902516579 posted


    I suggest looking in your Application Event Log to see if there is an error logged there.  You can also enable Failed Request Tracing to see where the request is hanging.  It's hard to know what the problem is without knowing what you DLL is doing.

    HTH, Ben

    • Marked as answer by Anonymous Thursday, October 7, 2021 12:00 AM
    Friday, February 8, 2013 9:26 AM