Question Re: Frustrating Error - Please Help in Technology Q&A

Frustrating Error - Please Help

Former Member — Tue, 19 Oct 2010 22:40:48 GMT

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:

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

Exception:

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:

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

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

Re: Frustrating Error - Please Help

Former Member — Wed, 20 Oct 2010 00:32:29 GMT

Hello,

Please mention the service pack of CR 2008 you are on?

Run [Process Monitor|http://technet.microsoft.com/en-ca/sysinternals/bb896645.aspx] when your application fails.

[Modules|https://smpdl.sap-ag.de/~sapidp/012002523100006252802008E/modules.zip] will be a great help to check the environment details of both scenarios.

Also try to close and dispose the report objects.

Thanks,

Saurabh

Re: Frustrating Error - Please Help

Former Member — Wed, 20 Oct 2010 00:41:36 GMT

I will try to run process monitor which I have not ever done... I am using sp3 and just tried installing sp3 fix pack 31 and it hasn't resolved the issue. The strange part of it all is how inconsistent the exception is. I actually get a different exception when I try to close and dispose.

Re: Frustrating Error - Please Help

Former Member — Wed, 20 Oct 2010 00:58:18 GMT

Could you please paste few errors or exceptions?

Thanks,

Saurabh

Re: Frustrating Error - Please Help

Former Member — Wed, 20 Oct 2010 01:08:53 GMT

its strange, after installing sp3fp31, instead of getting the exception upon load, i get the following exception when i drill down on data within a report (like an on-demand report), again very inconsistently... I just dont get what the variable is making it only throw exceptions 20% of the time. ill hit a sub report, it will work. i close it and hit it again,and it throws the following:

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 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.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)

CrystalDecisions.Windows.Forms

Assembly Version: 12.0.2000.0

Win32 Version: 12.3.2000.601

CrystalDecisions.Shared

Assembly Version: 12.0.2000.0

Win32 Version: 12.3.2001.684

CrystalDecisions.ReportSource

Assembly Version: 12.0.2000.0

Win32 Version: 12.3.2000.601

CrystalDecisions.CrystalReports.Engine

Assembly Version: 12.0.2000.0

Win32 Version: 12.3.2000.601

Re: Frustrating Error - Please Help

Former Member — Thu, 21 Oct 2010 00:35:38 GMT

Well after another day, I'm stilling battling this with no progress. I don't believe a close / dispose is necessary, as doesn't closing the app do that? It's a single EXE that loads a report into the viewer. It works fine 80% of the time, then I close it, open it again, and boom, I get the exception above. I just tested this and received it on a Windows 7 system with the CR 2008 SP3 FP 31 runtime loaded and got the exception twice.

I'm surprised I'm the only one who has seen this, I saw a few other posted the referenced the error message and there wasn't much resolution to their problem either.

The report loads, and the parameters show, and most of the time, the report shows fine. Sometimes I'll get that exception immediately after pressing OK on the parameter screen, and other times the report will load, and I'll get that exception when clicking on an on-demand report.

Again, if anyone could shed light on this, you would be a forum god. Thanks again.

Matt

Re: Frustrating Error - Please Help

Former Member — Thu, 21 Oct 2010 14:13:01 GMT

Here is my attempt at forum godhood :). So, let's think about this;

We essentially have two parts to this app; the report and the database.

The issue appears to be quite rare - not only are you the lucky one, but it happens quite randomly and not regularly.

You have the latest CR updates.

Maybe it's time to look at the database? Thinking about what is happening when you get these exceptions; running the repot (= db connection), drill down (= another DB hit), this may not be a bad idea to think about.

Which leads to a few questions / suggestions;

1) What database are you using?

2) How are you connecting to the database (OLE DB, ODBC, etc)

3) Is the DB client using the latest Service Pack / update

4) Can you change the connection type - say from ODBC to OLE DB - if only as a test?

5) Is the subreport using the same database and connection type?

6) Is the issue happening on subreport drill down, or any drillable field?

7) Is the issue now isolated to drill downs only?

😎 See if enabling the option "Verify on First Print" and "Verify Stored Procedure on First Print" will help (File |Report Options)

9) Is the database changing? E.g.; is your app modifying the database at the same time (give or take a milisecond) as the report is attempting to inhale the data?

Going back to the report. Remove the subreport. Save the report. Reinsert the subreport. See if that changes things.

Ludek

Re: Frustrating Error - Please Help

Former Member — Thu, 21 Oct 2010 14:26:45 GMT

Very good advice, I've actually started question whether or not it is the report as well. All the reports connect through ODBC. Some reports use MSSQL ODbC drivers and some use MySQL ODBC drivers, and in both cases I come across the error.

I'm going to run through your list and narrow this down the best I can, and do some more testing. One thing that is certain is that I don't get the error when running the report in crystal reports 2008 sp3 (the designer).

I'll post my findings here, thanks again, you may be close to god like status

Re: Frustrating Error - Please Help

Former Member — Wed, 03 Nov 2010 17:03:38 GMT

I am curious why the exception happens on OnMouseMove. do you have an event handler for MouseMove?

Re: Frustrating Error - Please Help

former_member208657 — Wed, 03 Nov 2010 21:08:36 GMT

I don't know if this is a typo or not. But I noticed you didn't declare your Report as a New object. I program in C# and it will always throw an "object reference ... " error if I don't instantiate my objects. This doesn't actually explain why it works some of the time though. I'd expect it to fail all the time.

Original Code


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

Added New


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

Dim Report As New CrystalDecisions.CrystalReports.Engine.ReportDocument
Report.Load("c:\report.rpt")

crystalreportviewer_main.ReportSource = Report

End Sub

Re: Frustrating Error - Please Help

ido_millet — Mon, 13 Dec 2010 19:51:40 GMT

I see this thread is marked as solved. Could you report back on what the solution was? I'm seeing this behavior in a scenario that doesn't involve data retrieval. The report is already rendered with data. A drill-down works OK, but a drill-down within that drill-down causes this failure. Top of the stack is:

System.NullReferenceException was unhandled

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

Source="CrystalDecisions.Windows.Forms"

StackTrace:

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

My winform app (vb.net 2008, Crystal 2008) doesn't have an OnMouseMove event so this looks like an internal viewer event that is blowing up.

Re: Frustrating Error - Please Help

Former Member — Wed, 12 Jan 2011 16:41:18 GMT

Hi,

sorry for replying to an old thread, but I didn't find a newer one where this problem is discussed.

Has there already been a solution for this?

I have this problem with CRVS2010, I get a NullReferenceException with an onMouseOver event without any reason sometimes when opening the crystal report viewer control at runtime.

Best regards

Re: Frustrating Error - Please Help

Former Member — Wed, 12 Jan 2011 16:53:39 GMT

I've not yet resolved this, but I applied FixPack 3.2 on my development system and then distributed the FixPack 3.2 runtime and the error seems to have become much less frequent. I would have thought 2010 addressed this because it seems like a straight up bug in the control.

Edited by: mlager on Jan 12, 2011 5:53 PM

Edited by: mlager on Jan 12, 2011 5:54 PM

Re: Frustrating Error - Please Help

Former Member — Wed, 12 Jan 2011 17:31:20 GMT

As we all know, the problem with fixing any reported bug is that any technical support receiving a bug report from a customer needs to be able to reproduce the issue. While there are a number of posts on the issue, neither I not anyone else here has been able to reproduce the issue.

This may boil down to someone obtaining a phone case and sharing a copy of their image. E.g.; I suspect this is a specific environment issue. And I hope it's not a specific hardware issue or a combination of hardware and environment.

- Ludek

Re: Frustrating Error - Please Help

Former Member — Fri, 14 Jan 2011 07:24:01 GMT

@Ludek:; if problem cannot be reproduced by your dev's team we did give you alot of information where and how this error pop-up.

Its on loading report, before report show there is message saying something "procesing..." and then we got specific error "onMouseMove". I dont think you have many events on mouseMove.

I cannot reproduce it at my wokr eather and its becouse our computer are much faster than custumores one and that loading screen is very short almoust instantly while at customers that "processing" message somethines can be few sec long.

Re: Frustrating Error - Please Help

Former Member — Fri, 14 Jan 2011 15:40:30 GMT

Understood. But I can get the a long report load time duplicated on skookum fast machine by simply running a complicated report. Say one that has a 1,000 + formulas. And no crash...

You your self say that you can not reproduce it. So yes, we have been given a lot of info on how to and I appreciate that, but if you can not repro it, I'm not sure what we should be doing(?). I'll take any ideas - other than; go get a really old slow box :).

I have a feeling that this will boil down to video drivers, video resolution, mouse drivers, some other drivers (printer?) and or combination there off.

Ludek

Edited by: Ludek Uher on Jan 14, 2011 7:40 AM

Re: Frustrating Error - Please Help

Former Member — Fri, 14 Jan 2011 15:47:50 GMT

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.

Re: Frustrating Error - Please Help

ido_millet — Fri, 14 Jan 2011 16:07:45 GMT

Hi Ludek,

Since you opened the door (requesting ideas), there is a clear unhandled exception in a clearly identified internal event. Ask the development team to catch and quietly handle that exception.

My guess is that they are using an event argument to instantiate an object that has not yet materialized. The detail is not that important. What's important is that ANY "Developer" worth that title should be able to resolve this bug within 1 hour of work.

Re: Frustrating Error - Please Help

Former Member — Tue, 18 Jan 2011 08:15:43 GMT

Exactly !

Solving this problem with your developers wont be much of a problem, we can catch excaption too and silently ignore it but its not way that should be done. In all forms i have viewer to code error exception that will be, probably, solved is not solution i am looking forward.

This is really frustrating and if we can get info will this be fixed soon or not. If it wont be in near future i will have to handle it in my application and all other users will have to do the same. (dont you think its something wrong with that solution?)

Re: Frustrating Error - Please Help

Former Member — Tue, 18 Jan 2011 15:56:48 GMT

How would you catch this exception? The control is throwing it outside of my user code... I've put my try statements around CRViewer.ReportSource = "..." but that doesn't catch the exception. Just curious how you would handle this.