Last post Jul 19, 2017 02:07 PM by march11
Sep 05, 2007 10:25 AM|Peter Lee|LINK
I'm using Visual Studio 2005 Team Edition, and am running across an annoying error:
Error Rendering Control - UpdatePanel1
An unhandled exception has occurred. Object reference not set to an instance of an object.
Here is the simplest way to reproduce the problem:
1) Create an Ajax Enabled Web App
2) Add a ScriptManager in Designer
3) Add an update Panel in Designer
4) add a modal Popup Extender in Designer (not inside the UpdatePanel)
5) right click, and choose Refresh
That consistently breaks the rendering of the update panel on my machine, and one of my friend's machines who is also running in the same environment.
AjaxControlToolkit Version 1.0.10618.0
System.Web.Extensions Version 1.0.61025.0
In case this is a bug, what is the procedure for reporting it? I think that AjaxControlToolkit is handled on CodePlex at:
But, I think that this is a problem with Update Panel, and UpdatePanels are a part of System.Web.Extensions, not AjaxControlToolkit's dll. Are they separate projects, and do I report bugs in different places, in case it is a bug?
Oct 11, 2007 11:24 AM|apollolax123|LINK
First upgrade to the newest version of AJAX Version # 10920. This should alleviate your woes. You are still on the version that was released on 6/18.
Oct 11, 2007 03:42 PM|Peter Lee|LINK
I am now referencing a newly built AjaxControlToolkit.dll, version 1.0.10920.24997
My Update Panel version is still: 1.0.61025.0, even after redownloading the latest installation package for web extensions.
I downloaded both today 10/11/2007.
I'm still getting the same error. If we can't figure it out, I think I can live with it. To get rid of the rendering error in design mode, I just need to close the .aspx page and reopen it.
Oct 11, 2007 10:57 PM|dwhite|LINK
That's correct... The UpdatePanel is not part of the AjaxControlToolkit, it's in System.Web.Extensions (GAC).
Try some of the tips here to see if you problem goes away:
Also, make sure there aren't any syntax errors in your code, like an unclosed tag or something...
Oct 15, 2007 10:07 AM|Peter Lee|LINK
I appreciate your response.
The link you sent discussed:
"Controls Not Compatible w/ UpdatePanel – another very common problem is with controls not operating as expected within the UpdatePanel. Looking at the
UpdatePanel Control Overview in the docs, have a look at the section titled "Controls that Are Not Compatible with UpdatePanel Controls". The most common issue with controls seems to be the Validators. Looking at the docs, you can "fix" the validators by
simply setting the EnableClientScript property to "false". Also there are ASP.NET AJAX compatible validators in the in the works, see
Matt Gibbs blog for more information on this. "
And the link to Microsoft's site on that blog says:
"The following ASP.NET controls are not compatible with partial-page updates, and are therefore not supported inside an
Web Parts controls. For more information, see
ASP.NET Web Parts Controls.
FileUpload controls when they are used to upload files as part of an asynchronous postback.
DetailsView controls when their EnableSortingAndPagingCallbacks property is set to
true. The default is false.
PasswordRecovery, ChangePassword, and
CreateUserWizard controls whose contents have not been converted to editable templates.
The Substitution control.
Validation controls, which includes the
There seem to be still a lot of problems with UpdatePanels (in .net 2.0). Though modalpopupextender is not listed as an incompatible control, it should probably be put on that list. It also does not have an enableClientScript property to set to false,
as the first link suggested for validators. Also, I do not have syntax errors in my code, because, all I did were the steps in my first post, dragging and dropping controls onto the page with no hand typed code.
Also, I found the answer to one of my questions, namely where to report .NET bugs, of which System.Web.Extensions is a part (I assume). To report a bug, go to:
I'm sorry I couldn't honestly mark anything as an answer. I'm going to go ahead and close this ticket, now that I've at least found where to report bugs, marking this post as an answer (btw, I won't get any points for it since it's my post, I know).
Thanks for all your suggestions, and willingness to help.
P.S.: I found a permanent "fix" for this problem with modalpopuextender and updatepanel. Evidently Microsoft fixed this in visual studio 2008 and .net 3.5, with the ajaxcontroltoolkit built for .net 3.5, using .net 3.5. Evidently, this will be fixed
in the future, and ready for use once visual studio 2008 and .net 3.5 get out of beta.
Dec 05, 2007 03:33 PM|srieen|LINK
Did you able to get rid from the above problme ? iam also facing the same.
Please let me know when u get any solution for this issue.
Dec 06, 2007 09:31 AM|Peter Lee|LINK
Yes, I did find a resolution to this issue, I mentioned it above in my message, but here it is quoted:
"P.S.: I found a permanent "fix" for this problem with modalpopuextender and updatepanel. Evidently Microsoft fixed this in visual studio 2008 and .net 3.5, with the ajaxcontroltoolkit built for .net 3.5, using .net 3.5. Evidently, this will be fixed
in the future, and ready for use once visual studio 2008 and .net 3.5 get out of beta."
At the time, I tested this with the beta version of VS 2008, and as I recall it didn't suffer from the same problem with the update panel and other extenders not rendering in design time. I haven't had a chance to install VS 2008 release yet, which was
released on 11/19/2007, but I assume it will fix this problem in that version also.
Alternatively, if you don't want to buy or download VS 2008, you could try using .net framework 3.5 with VS 2005, and see if it's really the framework that fixes the error. I suspect it may be an update in System.Web.Extensions in 3.5 that fixes it, and
that it is unrelated to the AjaxControlToolkit.dll
Feb 17, 2009 03:40 PM|Ladybugf8|LINK
Not so. I'm using VS2008 and .net 3.5. I'm getting the "Error: Rendering Control. An unhandled exception has occurred. Object reference not set to an instance of an object." message when I try to use an image hyperlink. It runs fine, just plays havoc on
getting the GUI the way I want it. I've tried opening and closing the .aspx file--didn't work. Any ideas on how to fix that?
Mar 01, 2009 12:22 PM|timetrips|LINK
I agree with LadyBugf8, I'm getting the error on my hyperlinks that use images. I'm on VS2008 with .net 3.5. This is very annoying. I'm seeing this in a master page after I added the asp:ScriptManager control. Not sure if they are 100% related but it
is a suspious coincidence. I'm still researching the problem so if anyone happens to resolve it a follow up post would be helpful. If I can't find anything today I may post a formal question here.
Apr 29, 2009 11:23 AM|ShaggyDogg|LINK
Apr 29, 2009 11:23 PM|chetan.sarode|LINK
See if anything here helps you:
Check your web.config
Also check for respective AJAX Control Toolkit version
Jul 19, 2017 02:07 PM|march11|LINK
This ling will explain the need link references...