Unhandled exception - just in time debugging

07-12-2012 02:02 PM
New Contributor III
I have an application (extension) that works fine on Windows XP platform. When I run this application on Windows 7 it throws this error. I am not sure what is causing this. I was thinking that it could be due to the fact that .net framework is not installed but I can see all in there. Looking for any ideas to resolve this issue.

Note: this error comes up when I click on a combox box. How can i get past this message box and get to actual error.

Thanks Jay

See the end of this message for details on invoking just-in-time (JIT) debugging instead of this dialog box.

***** Exception Text ******* System.NullReferenceException: Object reference not set to an instance of an object. at MapExt_Net.HEI_Extensions.layout.frmLayout.DisplaySize() at MapExt_Net.HEI_Extensions.layout.frmLayout.cBLayoutExtent_SelectedIndexChanged(Object sender, EventArgs e) at System.Windows.Forms.ComboBox.OnSelectedIndexChanged(EventArgs e) at System.Windows.Forms.ComboBox.WmReflectCommand(Message& m) at System.Windows.Forms.ComboBox.WndProc(Message& m) at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m) at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m) at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)

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Regular Contributor II
There is a bunch of context information missing.  Is this engine, server or desktop?  What is the combo box doing.  What components are being loaded.  Are your two system 64 or 32 bit. 
It looks like you don't have proper exception handling in your form event handlers.  Exception handlers might give you a better clue as to what is happening.  Also is your development environment on Win7?  It is very difficult to develop on one OS and deploy on a different one.
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