Our project  works fine with .Net 3.5  with Telerik 2009.2.701.35  version.

When it is migrated to .Net 4.5 framework.  
It throws error like this.
"0x800a139e - Microsoft JScript runtime error: Sys.WebForms.PageRequestManagerServerErrorException: 
Object reference not set to an instance of an object."

Detailed Error message is given.


Unhandled exception at line 3, column 69963 in http://localhost:57537/...../Telerik.Web.UI.WebResource.axd?_TSM_HiddenField_=ctl00_DefaultMasterScriptManager_TSM&compress=1&_TSM_CombinedScripts_=;
;AjaxControlToolkit,+Version=4.5.7.725,+Culture=neutral,+PublicKeyToken=28f01b0e84b6d53e:en-US:f3ec7948-9e31-4562-b526-b0088d3f7327:
ea597d4b:b25378d2;Telerik.Web.UI,+Version=2013.1.417.45,+Culture=neutral,+PublicKeyToken=121fae78165ba3d4:
en-US:42f3bd03-686e-4514-94d4-9dc03944a160:16e4e7cd:ed16cbdc:f7645509:24ee1bba:19620875:874f8ea2:f46195d3:490a9d4e:bd8f85e4:
2003d0b8:e330518b:1e771326:c8618e41:b7778d6c:e085fe68:8e6f0d33:6a6d718d:8674cba1:7c926187:c08e9f8a:a51ee93e:59462f1:
aa288e2d:82923ac3:58366029

0x800a139e - Microsoft JScript runtime error: Sys.WebForms.PageRequestManagerServerErrorException: 
Object reference not set to an instance of an object.

If there is a handler for this exception, the program may be safely continued.




So it is upgraded to Telerik  2013.1.417.45 version.  It is throwing  same error.  [Even tried with Latest Telerik AspnetAjax Q2 version is also throwing the same error]


I suspect that the error might be because the AjaxRadManager  and/or  skins which is implemented from  Telerik.Web.UI. Skins.dll  is causing the 
trouble. 
 

Based on feedback received from our customer, we can further improve our TypeScript definitions - the main concern is that there are still missing methods and incorrect signatures.

Using a hidden button and calling its .click() method is sometimes used to invoke a postback under some application logic conditions. If you use the jQuery method and a RadAjaxPanel, this will no longer work with jQuery3 because its strict mode causes the MS AJAX scripts to throw an error.

Below is a sample repro of the scenario and it shows two of the workarounds. The third workaround is to downgrade jQuery to an older version (for example, 1.11.1 which is the previous version the suite used): https://docs.telerik.com/devtools/aspnet-ajax/controls/scriptmanager/disabling-the-embedded-jquery


        <telerik:RadScriptManager ID="RadScriptManager1" runat="server">
            <Scripts>
                <asp:ScriptReference Assembly="Telerik.Web.UI" Name="Telerik.Web.UI.Common.Core.js" />
                <asp:ScriptReference Assembly="Telerik.Web.UI" Name="Telerik.Web.UI.Common.jQuery.js" />
                <asp:ScriptReference Assembly="Telerik.Web.UI" Name="Telerik.Web.UI.Common.jQueryInclude.js" />
            </Scripts>
        </telerik:RadScriptManager>
        <telerik:RadCodeBlock runat="server" ID="rcb1">
            <script>
                function clickHiddenButton1() {
                    $telerik.$("#<%=Button1.ClientID%>").click();
                    //workaround 1
                    //__doPostBack("<%=Button1.UniqueID%>", "");
                    //workaround 2
                    //$find("<%=rap1.ClientID%>").ajaxRequest();
                }
            </script>
        </telerik:RadCodeBlock>
        <asp:Button Text="click hidden button" ID="testButton1" OnClientClick="clickHiddenButton1(); return false;" runat="server" />
        <telerik:RadAjaxPanel runat="server" ID="rap1" OnAjaxRequest="rap1_AjaxRequest">
            <asp:Label Text="" ID="Label1" runat="server" />
            <asp:Button Style="display: none;" Text="hidden button" ID="Button1" OnClick="Button1_Click" runat="server" />
        </telerik:RadAjaxPanel>

Had a go to meeting to discuss Telerik tools integration with Desislava Nikolo and another consultant. They acknowledged this issue and resolved to contact me after the meeting to provide a fix. 
Basically, from the Telerik Tab in the IDE 2010, I am unable to load any of the RAD tools for development.

When i init ajaxmanager ajaxRequest from client side radprogressmanager starts its unstoppable progress callbacks and overloads IIS. Please find the attached code to reproduce the issue. Run App and run chrome/ firefox debugger, wait for 2 mins for timer to init ajax request as required and then you can see radprogress unstoppable callbacks. 

Webpage error details

User Agent: Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.1; Trident/4.0; GTB7.5; .NET CLR 2.0.50727; .NET CLR 3.0.4506.2152; .NET CLR 3.5.30729; .NET4.0C; .NET4.0E)
Timestamp: Tue, 5 Nov 2013 20:08:42 UTC


Message: Expected identifier
Line: 541
Char: 18
Code: 0
URI: http://test/Telerik.Web.UI.WebResource.axd?_TSM_HiddenField_=rsmMain_TSM&compress=1&_TSM_CombinedScripts_=%3b%3bSystem.Web.Extensions%2c+Version%3d4.0.0.0%2c+Culture%3dneutral%2c+PublicKeyToken%3d31bf3856ad364e35%3aen-US%3ac9cbdec3-c810-4e87-846c-fb25a7c08002%3aea597d4b%3ab25378d2%3bRMSWeb%3aen-US%3affbcc4ad-6e36-47e9-bd28-56e10d4d3ccd%3a43e04e1c%3ae90c43c6%3ac2fa243f%3a748e57f2%3bLAO.Web%3aen-US%3a789e0dea-6f9a-4c0f-a1db-5b64c6e6f0d7%3ad16f8f2a%3ae282b917%3bTelerik.Web.UI%2c+Version%3d2013.3.1015.45%2c+Culture%3dneutral%2c+PublicKeyToken%3d121fae78165ba3d4%3aen-US%3a7a1d9c2d-6cf2-464f-9ad3-e479c730ac61%3a16e4e7cd%3aed16cbdc%3af7645509%3a24ee1bba%3a874f8ea2%3af46195d3%3a92fe8ea0%3a19620875%3afa31b949%3a490a9d4e%3abd8f85e4%3a88144a7a%3a1e771326%3a4cacbc31%3a2003d0b8%3ae524c98b%3aa7e79140%3ab7778d6c%3a7165f74%3a58366029%3aaa288e2d 

The Ajax in the sample page is made using:

$find("<%= RadAjaxManager.GetCurrent(Page).ClientID %>").ajaxRequest();

In on the page the AjaxManger updates the panel, in the other the setting is that the proxy should update the panel. This is invalid setting.

<telerik:AjaxSetting AjaxControlID="RadAjaxManagerProxy1" >
    <UpdatedControls>
        <telerik:AjaxUpdatedControl ControlID="rsLeftPanel" LoadingPanelID="ralp1" />
    </UpdatedControls>
</telerik:AjaxSetting>

The correct way of doing this is to use add the settings programatically, or to use the ajaxRequestWithTarget instead of ajaxRequest method
http://docs.telerik.com/devtools/aspnet-ajax/controls/ajax/radajaxmanager/how-to/add-ajaxsettings-programmatically

A grid in a RadAjaxPanel will fire several requests when exporting if there is a RadAjaxManager on the page as well.

Stems from the _setupExclusionFilters function where each RadAjaxControl adds as a handler to Sys.WebForms.PageRequestManager.getInstance().add_initializeRequest which does a  sender._form.submit(); and gets called in the initialize method of the control.

The resolution is to use only RadAjaxManager to AJAX-enable complex pages that require the built-in exports as well and make sure to remove all RadAjaxPanel instances. This is the better approach anyway: http://docs.telerik.com/devtools/aspnet-ajax/controls/ajaxmanager/troubleshooting/controls-wrapped-in-ajaxpanel-and-added-to-ajaxmanager-settings

Repro and example solutions are added in the file attached below.

We have code for our ajaxified submit forms to disable the submit button on request start and re-enabled it on request end. This used to work, but when we upgraded to the latest build (2020.2.617), setting the disabled property to false now throws an error in IE from the WebResource.axd file (does not appear to have a problem in Firefox). The attached demo project shows exactly where the error occurs. Just click the Search button.

Attached picture shows an example of the error message thrown. The error does not appear to be with our javascript code itself; all the variables are populated and valid. It looks like something is getting triggered in the WebResource code when we set the disabled property to false and that is where the break is occurring.

Attached is a reproduction project page with a <script> containing a workaround.

Reproduction steps:

1) Run the page

2) Hover quickly between the two colored squares (do this up to 15-20 seconds)

3) Observe the error in the browser's console:

Uncaught RangeError: Maximum call stack size exceeded
    at Function.Array.addRange 
    at Telerik.Web.UI.RadAjaxManager._executePendingRequest 
    at Object._endRequest 
    at Array.<anonymous> 
    at Sys.WebForms.PageRequestManager._endPostBack 
    at Sys.WebForms.PageRequestManager._scriptsLoadComplete 
    at Sys.WebForms.PageRequestManager.<anonymous>   
    at Sys._ScriptLoader._loadScriptsInternal 

Workaround: Place/load this script somewhere after the ScriptManager of the page

<script>
    Telerik.Web.UI.RadAjaxControl.prototype._executePendingRequest = function () {
        var pendingRequest = Array.dequeue(this._requestQueue);

        var eventTarget = pendingRequest[0];
        var eventArgument = pendingRequest[1];

        if (this._requestQueue.length > 0 && this.__id != "") {
            var currentAjaxControl = $find(this.__id);
            if (currentAjaxControl) {
                Array.addRange(currentAjaxControl._requestQueue, this._requestQueue);
                // optional, uncomment if issue persists
                //if (currentAjaxControl._requestQueue.length > currentAjaxControl._requestQueueSize) {
                //    // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/slice#parameters 
                //    // using negative index for start to get the last N elements
                //    currentAjaxControl._requestQueue =
                //        currentAjaxControl._requestQueue.slice(-currentAjaxControl._requestQueueSize)
                //}
            }
        }

        var requestManager = Sys.WebForms.PageRequestManager.getInstance();
        requestManager._doPostBack(eventTarget, eventArgument);
    }
</script>

args.get_eventTargetElement() in OnRequestStart event returns null when Paging the Grid initiates an AjaxRequest via AjaxManager

How do I determine if the event target is a RadGrid?

The following code leads to a JavaScript error

<telerik:RadAjaxManager ID="RadAjaxManager1" runat="server" ClientEvents-OnRequestStart="requestStart">
    <AjaxSettings>
        <telerik:AjaxSetting AjaxControlID="RadGrid1">
            <UpdatedControls>
                <telerik:AjaxUpdatedControl ControlID="RadGrid1" />
            </UpdatedControls>
        </telerik:AjaxSetting>

JavaScript

function requestStart(sender, args) {
    var target = args.get_eventTargetElement();
    if (target.className.indexOf("RadGrid") > -1) {
        // RadGrid control
    }
}

When a RadContol is placed into a RadAjaxPanel, its method DescribeComponent is fired twice on postback.

Running for the firts time, the calendar displays correctly the things i want to; but if I navigate to another monts in the calendar, the event is is not fired, so the render of the things I want seems not to work.

This si the code:

Protected Sub RadCalendar1_DayRender(ByVal sender As Object, _
ByVal e As Telerik.Web.UI.Calendar.DayRenderEventArgs) _
Handles RadCalendar1.DayRender
    Dim CurrentDate As DateTime = e.Day.[Date]
    If CurrentDate.Month <> RadCalendar1.FocusedDate.Month Then
        e.Cell.Text = "(" + CurrentDate.Day + ")"
    ElseIf e.Day.IsToday Then
        e.Cell.Style("background-color") = "Red"
    End If
End Sub

Thanks