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]

I'm new to this thread, but I'm getting the same onMouseMove error. I upgraded from VS/Crystal 2005 to VS/Crystal 2010. Never had this issue till the upgrade. Let me know if there is anything I can do to get this resolved. Thanks.

[Former Member]

I am also getting inconsistent a NullReferenceException with an onMouseOver event without any reason sometimes when opening the crystal report viewer control at runtime.

Just installed SP1 . It has no affect . still have this error from time to time. it seems like a straight up bug in the control. Is any way to catch this error?

[Former Member]

No way to catch the error. Go through my post on how to work-around the issue. In a nut shell, this is caused by formula(s) in the report. You have to find out which one(s) and place the formula(s)s in a text box. I have managed to resolve the issue for two customers in this way.

The issue has been reported to R&D and it is "fixed". However the fix will not be released until SP 2 (June \ July time frame).

- Ludek

[Former Member]

Hi Ludek,

Since I have removed the <Close> button from our viewer form the frequency of the error has reduced from every 1/2 hour to once a day.

Thanks for your efforts to fix the formulae in the Crystal report example we sent. As you know the changes did not fix the problem in this report (NB. We have approx 40 other reports in our application).