Hello everyone,

I have been working with an Umbraco 4.9 web site. I have been running C# code for it and compiling it through Visual Studio, then I was able to test it by using "Attach to Process" -> w3wp.exe.

Until I made the grave mistake of installing an Extension for VS called ".NET Reflector", because I wanted to try it for another project in VS. Then I came back to developing on the site. I compiled my code for the site only once with that extention installed in VS... then I started having this error every time I tried to "Attach to Process":

System.NullReferenceException occurred
  Message=Object reference not set to an instance of an object.
  Source=umbraco
  StackTrace:
       at umbraco.page..ctor(XmlNode xmlNode)
  InnerException: 

Call stack:

    umbraco.dll!umbraco.page.page(System.Xml.XmlNode xmlNode = {System.Xml.DebuggerDisplayXmlNodeProxy}) + 0xa83 bytes 
> umbraco.dll!umbraco.UmbracoDefault.Page_PreInit(object sender = {ASP.default_aspx}, System.EventArgs e = {System.EventArgs}) + 0xdfd bytes 
    System.Web.RegularExpressions.dll!System.Web.Util.CalliHelper.EventArgFunctionCaller(System.IntPtr fp, object o, object t, System.EventArgs e) + 0x19 bytes    
    System.Web.dll!System.Web.UI.Page.PerformPreInit() + 0x31 bytes    
    System.Web.dll!System.Web.UI.Page.ProcessRequestMain(bool includeStagesBeforeAsyncPoint = true, bool includeStagesAfterAsyncPoint = true) + 0x6b4 bytes    
    System.Web.dll!System.Web.UI.Page.ProcessRequest(bool includeStagesBeforeAsyncPoint, bool includeStagesAfterAsyncPoint = true) + 0xc1 bytes    
    System.Web.dll!System.Web.UI.Page.ProcessRequest() + 0x10d bytes   
    System.Web.dll!System.Web.UI.Page.ProcessRequest(System.Web.HttpContext context) + 0xa7 bytes  
    App_Web_default.aspx.cdcab7d2.shiikmje.dll!ASP.default_aspx.ProcessRequest(System.Web.HttpContext context = {System.Web.HttpContext}) + 0x33 bytes C#
  System.Web.dll!System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() + 0x271 bytes   
    System.Web.dll!System.Web.HttpApplication.ExecuteStep(System.Web.HttpApplication.IExecutionStep step = {System.Web.HttpApplication.CallHandlerExecutionStep}, ref bool completedSynchronously = false) + 0x10e bytes   
    System.Web.dll!System.Web.HttpApplication.PipelineStepManager.ResumeSteps(System.Exception error) + 0x6f5 bytes    
    System.Web.dll!System.Web.HttpApplication.BeginProcessRequestNotification(System.Web.HttpContext context, System.AsyncCallback cb) + 0x85 bytes    
    System.Web.dll!System.Web.HttpRuntime.ProcessRequestNotificationPrivate(System.Web.Hosting.IIS7WorkerRequest wr = {System.Web.Hosting.IIS7WorkerRequest}, System.Web.HttpContext context = {System.Web.HttpContext}) + 0x2b6 bytes 
    System.Web.dll!System.Web.Hosting.PipelineRuntime.ProcessRequestNotificationHelper(System.IntPtr managedHttpContext, System.IntPtr nativeRequestContext = 21719144, System.IntPtr moduleData, int flags) + 0x3bf bytes 
    System.Web.dll!System.Web.Hosting.PipelineRuntime.ProcessRequestNotification(System.IntPtr managedHttpContext, System.IntPtr nativeRequestContext, System.IntPtr moduleData, int flags) + 0x22 bytes   
    [Native to Managed Transition] 
    [Managed to Native Transition] 
    System.Web.dll!System.Web.Hosting.PipelineRuntime.ProcessRequestNotificationHelper(System.IntPtr managedHttpContext, System.IntPtr nativeRequestContext, System.IntPtr moduleData, int flags) + 0x4f4 bytes    
    System.Web.dll!System.Web.Hosting.PipelineRuntime.ProcessRequestNotification(System.IntPtr managedHttpContext, System.IntPtr nativeRequestContext, System.IntPtr moduleData, int flags) + 0x22 bytes   
    [Appdomain Transition] 

The site works fine with the code I build, but I have no way of testing any of the C# functionality right now because of this Attach to Process problem...
I already tried : Uninstalling the extension, deleting all remaining files in extention dir, restarting PC, restarting IIS and I have been digging through all sorts of .config files and through the Internet, but nothing helped so far.

Any suggestions would be welcome, I already spent a day on this issue and I have deadlines at work that I am already behind with. I am the only IT guy in the company so there is no colleague that could help.

PS. I don't understand how one extension could cause such a mess...