This sticky thread lists known issues and breaking changes introduced in the UI for ASP.NET AJAX releases.

• Q3 2011 (Version number: 2011.3.1115)
• Q1 2013 (Version number: 2013.1.220)
• Q2 2013 (Version number: 2013.2.611)
• Q2 2013 SP1 (Version number: 2013.2.717)
• Q3 2013 (Version number: 2013.3.1015)
• Q1 2014 (Version number: 2014.1.225)
• Q2 2014 (Version number: 2014.2.618)
• Q3 2014 (Version number: 2014.3.1024)
• Q1 2015 (Version number: 2015.1.225)
• Q2 2015 (Version number 2015.1.623)
  
• Q2 2015 SP1 (Version number: 2015.2.729)
• Q3 2015 SP1 (Version number: 2015.3.1111)
• Q1 2016 (Version number: 2016.1.113)
• Q1 2016 SP1 (Version number: 2016.1.225)
• R2 2016 (Version number: 2016.2.504)
• R2 2016 SP1 (Version number: 2016.2.607)
• R3 2016 (Version number: 2016.3.914)
• R3 2016 SP1 (Version number: 2016.3.1018) 
• R1 2017 (Version number: 2017.1.118)
• R1 2017 SP1 (Version number: 2017.1.228)
• R2 2017 (Version number: 2017.2.503)
• R2 2017 SP2 (Version number: 2017.2.711)
• R3 2017 (Version number: 2017.3.913)
• R1 2018 (Version number: 2018.1.117)
• R2 2018 (Version number: 2018.2.516)
• R2 2018 SP1 (Version number: 2018.2.710)
• R3 2018 (Version number 2018.3.910)
• R1 2019 (Version number: 2019.1.115)
• R3 2019 (Version number: 2019.3.916)
• R1 2020 (Version number: 2020.1.114)
• R3 2020 SP1 (Version number: 2020.3.1021)
• R1 2021 SP1 (Version number: 2021.1.224)
• R2 2021 (Version number: 2021.2.511)
• R2 2021 SP1 (Version number: 2021.2.616)
• R3 2021 (Version number: 2021.3.914)
• R3 2021 SP1 (Version number: 2021.3.1111)
• R2 2022 SP1 (Version number: 2022.2.622)
• R3 2022 (Version number: 2022.3.913)
• R1 2023 (Version number: 2023.1.314)
• 2024 Q1 (Version number: 2024.1.131)
• 2024 Q3 (Version number: 2024.3.805)
• 2024 Q4 (Version number: 2024.4.1113)
• 2024 Q4 (Version number: 2024.4.1114)
• 2025 Q1 (Version number: 2025.1.211)

Q3 2011 (Version number: 2011.3.1115)

Problem: When adding items to OData-enabled controls (RadMenu, RadTreeView, RadListBox, RadComboBox) through design time erroneous markup is applied to the control:

<telerik:RadListBox runat="server" ID="RadListBox1">
    <Items>
    </Items>
    <WebServiceSettings>
        <ODataSettings InitialContainerName="">
        </ODataSettings>
    </WebServiceSettings>
</telerik:RadListBox>

Please note the added ODataSettings section. It will cause JavaScript errors on the page.

When I run my project I'm getting this error

Could not load file or assembly 'Telerik.Web.UI' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)

In my web.config I checked that the version in the web.config is the same as the version I'm using in references

<assemblyIdentity name="Telerik.Web.UI" publicKeyToken="121fae78165ba3d4" culture="neutral" />
        <bindingRedirect oldVersion="0.0.0.0-2020.2.617.45" newVersion="2020.2.617.45" />

Hello

I have several RadGrids with custom css applied to the columns.  Everything works as intended.  However, when a column is sorted, telerik applied the .rgSorted css and this completely defeats the purpose of the gird (in our application).  What is the procedure to DISABLE or DELETE the .rgSorted css, as this particular class will never be needed or used. 

Note: any css class definition with !important cannot be used in this context.

Thank you

I checked the demo at https://demos.telerik.com/aspnet-ajax/window/examples/rendermodes/defaultcs.aspx?skin=MetroTouch with render mode set to classic in Chrome's Dev Tools > Mobile device emulator. I noticed a vertical line between the td cells in the title bar row as shown in screenshot below. I also noticed a similar issue with Metro skin in classic render mode. If I view the same in non-mobile mode in Chrome then this issue disappears. Perhaps, its some styling issue, but I could not find any CSS causing this.

It makes the title bar look non-uniform and not good in appearance.

What is causing the break among the td cells in the title bar for this case? (i.e. vertical line can be seen where the first td cell in title bar ends and then where the third td cell begins)

However, I did find a workaround solution using the  jquery code below. I executed this code in Chrome's Dev Tools > Sources tab under Watch, but it would be best to have this code in the beforeshow or show client-side event of the RadWindow being displayed in the demo.

$(".RadWindow:visible").each((index, emt) => {
    $(this).find("tr.rwTitleRow td.rwTopLeft, .RadWindow tr.rwTitleRow td.rwTopRight").css("display", "none");
    $(this).find("tr.rwTitleRow td.rwTitlebar").attr("colspan", "3");
});

I have encountered a niche issue I'm trying to solve. I have a grid with EnableViewState set to false. Based on this, the control state within the grid is used to manage things like sort expressions.

My issue is simply this:

1. Page load
2. Programmatically add columns to a grid
3. On the UI, sort on a column, and its name for example is 'My Column', this becomes 'My Column ASC'
4. On our app are objects in which its name we can add as a column to the same grid
5. Somewhere in our app I rename the object's name to something else like 'My New Column' - note the sort expression is still 'My Column ASC'
6. Back to the grid, I cause a postback (e.g., rebind) or reorder a column, or sort, etc.
7. The columns need to be re-added (I've covered a case to exclude the column with the old name)
8. Before columns are added again, I manually clear sort expressions on the grid
9. While debugging, I found that in the ColumnCreated event, the grid sort expressions restore to what they were before the postback, and I see 'My Column ASC' - I find that whenever adding a SortExpression referencing a non-existing column, the program always breaks

I debugged against a few events of the grid and found that in ColumnCreated (after NeedDataSource) the grid restored its sort expressions from what I presume is the control state. So, this was between NeedDataSource and ColumnCreated.

When exactly did the sort expressions get restored, and is there an event I can listen to?

I'm experiencing an issue where the page becomes unresponsive for a long time whenever any Telerik control (such as refresh or loader) is triggered. The page keeps loading indefinitely, causing significant delays, and eventually, the page becomes unresponsive.

Additionally, the following error appears in the browser console:

Uncaught Sys.WebForms.PageRequestManagerTimeoutException: Sys.WebForms.PageRequestManagerTimeoutException: The server request timed out.
at Error.create (https://test.plc.com/GS/Telerik.Web.UI.WebResource.axd?...:6:2736)
at Sys.WebForms.PageRequestManager._createPageRequestManagerTimeoutError (https://wpinhouse.knpc.com/GPCS/Telerik.Web.UI.WebResource.axd?...:15:11219)
at Sys.WebForms.PageRequestManager._onFormSubmitCompleted (https://wpinhouse.knpc.com/GPCS/Telerik.Web.UI.WebResource.axd?...:15:11219)

The issue arises when interacting with Telerik controls that trigger a page request, causing the page to hang and ultimately become unresponsive.

issue started from Feb 17 2025

After updating to the latest version (2025.1.218), I received an error on only one of my pages where I'm using the asp:RequiredFieldValidator.

The error stated that WebForms UnobtrusiveValidationMode requires a ScriptResourceMapping for 'jquery'...

Initially, I added the script mapping to the global.asax.cs page, but then discovered I could just disable UnobtrusiveValidation in the web.config.

The error was resolved with each of these solutions, but I wanted to get away from modifying the global.asax page, so I went with the web.config setting.

My questions are what has changed that led to this error, and which method is recommended?  What are the ramifications of simply disabling it in the web.config?

I am getting error "You are trying to navigate to a non-existing folder or you do not have proper permissions to view this folder.
Please, contact the administrator." in my production environment. It is happening randomly. 

Thanks.

got this error

'Could not load file or assembly 'Telerik.Web.UI, Version=2024.3.805.462, Culture=neutral, PublicKeyToken=121fae78165ba3d4' or one of its dependencies. Invalid pointer (Exception from HRESULT: 0x80004003 (E_POINTER))'