Question

I’m getting the following exception when I try to run up my Winforms app and haven’t been able to find a solution to it:

System.ArgumentNullException was unhandled
  Message=Value cannot be null.
Parameter name: activationContext
  Source=mscorlib
  ParamName=activationContext
  StackTrace:
       at System.Runtime.Hosting.ApplicationActivator.CreateInstance(ActivationContext activationContext, String[] activationCustomData)
       at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssemblyDebugInZone()
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean ignoreSyncCtx)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
       at System.Threading.ThreadHelper.ThreadStart()
  InnerException: 

I’ve added a handler for the “unhandled error” event in the applicationevents class but it never reaches that stage and there is no source code running that I can break into and diagnose.

The application was fine until I added a user control (nothing fancy, just a standard windows user control) and then dragged it onto a form in the app (user control and form were in the same application). The application builds and compiles without any errors or warnings but when I attempt to run it up I get the above error straight away.

Does anyone have any idea what it could be or even how I can go about investigating it? I’m a bit stumped on this one as I’m not sure how to investigate it. I removed the user control from the form and then I removed the user control from the application entirely but the error hasn’t gone away. In all honesty the addition of the user control might be a red herring but the problem manifested straight after adding it.

Hope someone can help.

Answer 1

try unchecking the Enable clickonce security settings checkbox in the security tab of the application properties(Projects Tab -> "Project Name" Properties-> Security Tab).