Hello

A customer of ours is having a problem running our software which we cannot reproduce on our machines. Application.Run() fails. The stack trace is

System.NullReferenceException: Object reference not set to an instance of an object.
at System.Windows.Forms.Form.get_IsMdiChild()
at System.Windows.Forms.Form.SetVisibleCore(Boolean value)
at System.Windows.Forms.Control.set_Visible(Boolean value)
at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)
at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)
at System.Windows.Forms.Application.Run(Form mainForm)
at MapStar.Program.Main()

Does anyone have any ideas on what the problem could be?

Thanks
Dominic

Send them a custom build with thorough logging, so you'd be able to pinpoint more closely where the exception is thrown.

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http://blog.voidnish.com

Thanks for the reply.

I don't understand what other logging I can do - the stack trace shows that the exception is thrown in Form.get_IsMdiChild(). How can I pinpoint it any more than that?

Hi,

I think you need to check which action invokes form.get_IsMdichild() method. Seems the form is not initialized or has been set to nothing or disposed before been used.

Best regards,

Ling Wang

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