Frustrating Error - Please Help

[#1]

I'm building a windows form app using vb.net, Visual Studio 2008, and CR 2008 (12.0.2000.0). I have a very simple app that loads a report into a viewer control when the form is loaded. About 80% of the time, the report loads with no issue. The other 20% of the time, I receive an exception which Visual Studio doesn't point out where in my code it is, so I'm assuming its the CR viewer that is throwing it. Here is the code I am using, and the associated exception is below. I can't for the life of me figure this out, and the issue has been replicated on a clean system running the CR 2008 SP3 Runtime. Any advice would be GREATLY appreciated.

VB Code:

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Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

Dim Report As CrystalDecisions.CrystalReports.Engine.ReportDocument

Report.Load("c:\report.rpt")

crystalreportviewer_main.ReportSource = Report

End Sub

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Exception:

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System.NullReferenceException was unhandled

Message="Object reference not set to an instance of an object."

Source="CrystalDecisions.Windows.Forms"

StackTrace: 3

at CrystalDecisions.Windows.Forms.PageControl.OnMouseMove(MouseEventArgs e)

at System.Windows.Forms.Control.WmMouseMove(Message& m)

at System.Windows.Forms.Control.WndProc(Message& m)

at System.Windows.Forms.ScrollableControl.WndProc(Message& m)

at System.Windows.Forms.ContainerControl.WndProc(Message& m)

at System.Windows.Forms.UserControl.WndProc(Message& m)

at CrystalDecisions.Windows.Forms.PageControl.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.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)

at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg)

at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(Int32 dwComponentID, Int32 reason, Int32 pvLoopData)

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(ApplicationContext context)

at Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.OnRun()

at Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.DoApplicationModel()

at Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.Run(String[] commandLine)

at Rock_Pond_Solutions.My.MyApplication.Main(String[] Args) in 17d14f5c-a337-4978-8281-53493378c1071.vb:line 81

at System.AppDomain._nExecuteAssembly(Assembly assembly, String[] args)

at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)

at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()

at System.Threading.ThreadHelper.ThreadStart_Context(Object state)

at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)

at System.Threading.ThreadHelper.ThreadStart()

InnerException:

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Edited by: mlager on Oct 20, 2010 12:41 AM

Edited by: mlager on Oct 20, 2010 12:44 AM

[Former Member]

Hmm .. "my guess" is that this error pop up most likely on slow machines and that is just and info that you could take in mind when debugging onMouseOver event in you viewer.

I cannot reporoduce it constantly .. i get like every 100 time error, but as on customers its constantly like 50 per day.

I dont know if viewer have any onMouseMove events tho it is some kind of chain message.