NullReferenceException in DispatchMessageW

[Chris Soulsby]

Hi,

I’m getting an exception when changing mdi child form. This does not happen all the time. I’m using the MDI tabbed control and also the parent\child XP menus. Has anyone come across this problem before?

System.NullReferenceException: Object reference not set to an instance of an object.
at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg)
at System.Windows.Forms.ComponentManager.System.Windows.Forms.UnsafeNativeMethods+IMsoComponentManager.FPushMessageLoop(Int32 dwComponentID, Int32 reason, Int32 pvLoopData)
at System.Windows.Forms.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)
at System.Windows.Forms.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)
at System.Windows.Forms.Application.Run()
at Sysinx.DM.SingleInstanceClass.CreateSingleInstance(SingleInstanceClassDelegate oOnInitialStartUp, SingleInstanceClassDelegate oOnMutipleInstances) in

[Administrator]

Hi Chris, I have created a test sample as per your specifications above, and have attached it here. Please try this on your machine and see if you can recreate the error. If possible, modify this sample to show the problem and send it back to us so that we could further investigate this issue. Also let me know the version of Essential Suite that you are using. Thanks for considering Syncfusion products. Regards, Guru Patwal Syncfusion, Inc.