Update license-errors-warnings.md

Author: nade7o

licensing/license-errors-warnings.md

@@ -11,6 +11,11 @@ position: 4
 
 Starting with the __2025 Q1 release__, using Telerik UI for .NET WinForms without a license or with an invalid license causes specific license warnings and errors. This article defines what an invalid license is, explains what is causing it, and describes the related license warnings and errors.
 
+A missing, expired, or invalid license will result in:
+  - A watermark appearing on application startup.
+  - A modal dialog appearing on application startup. Clicking the **OK** button of the dialog closes the dialog and removes the banner until the next application startup.
+  - A warning message can appear in the build log.
+
 ## Invalid License
 
 An invalid license can be caused by any of the following:
@@ -24,18 +29,24 @@ An invalid license can be caused by any of the following:
 
 ## License Warnings and Errors
 
-When using Telerik UI for .NET WinForms in a project with an expired or missing license, the `Telerik.Licensing` build task will indicate the following errors:
-
-| Error or Condition                              | Solution                                                                                      |
-|----------------------------------------|-----------------------------------------------------------------------------------------------|
-| `No license key is detected` | [Set up a license key]({%slug license-key%}) to activate the UI controls and remove the error message. | 
-| `Invalid license key` | [Download a new license key]({%slug license-key%}#downloading-the-license-key) and use it to activate the UI controls and remove the error message. |
-| `Your subscription license has expired.` | Renew your subscription and [download a new license key]({%slug license-key%}#downloading-the-license-key). |
-| `Your perpetual license is invalid.` | You are using a product version released outside the validity period of your perpetual license. To remove the error message, do either of the following: |
-|                                        | - Renew your license, then download a new license key and use it to activate the controls. |
-|                                        | - Downgrade to a product version included in your perpetual license as indicated in the message. |
-| `Your trial license has expired.`        | Purchase a commercial license to continue using the product. |
-| `Your license is not valid for the detected product(s).` | Review the purchase options for the listed products. Alternatively, remove the references to the listed packages from `package.json`. |
+When using Telerik UI for .NET WinForms in a project with an expired or missing license, the `Telerik.Licensing` build task will indicate the following errors or conditions:
+
+| Error or Condition           |Message Code   |Solution           |
+|:-----------------------------|:-----------:|:--------------------|
+| `No Telerik and Kendo UI License file found`           |TKL002   | [Install up a license key]({%slug license-key%}) to activate the UI components and remove the error message. | 
+| `Corrupted Telerik and Kendo UI License Key content` |TKL003      |[Download a new license key]({%slug license-key%}#downloading-the-license-key) and install it to activate the UI components and remove the error message. |
+|`Unable to locate licenses for all products`|TKL004|Your license is not valid for all Telerik and Kendo products added to your project. If you have already purchased the required license, then [update your license key]({%slug license-key%}#updating-your-license-key).|
+| `Telerik UI for .NET WinForms is not listed in your current license file.` |TKL101| Review the purchase options for the listed products. Alternatively, remove the references to the listed packages from `package.json`. |
+| `Your current license has expired.` |TKL102| You are using a product version released outside the validity period of your perpetual license. To remove the error message, do either of the following: <br> - Renew your subscription and [download a new license key]({%slug license-key%}#downloading-the-license-key) and use it to activate the controls. <br> - Downgrade to a product version included in your perpetual license as indicated in the message. |
+
+| `Your subscription has expired.`|TKL103; TKL104  | Renew your subscription and [download a new license key]({%slug license-key%}#downloading-the-license-key).|
+
+| `Your trial has expired.`    |TKL105   | Purchase a commercial license to continue using the product. |
+
+|`No Telerik or Kendo UI product references detected in project`|TKL001| 
+<br> - If you use Telerik products and see this message, update the Telerik.Licensing package to version 1.4.9 or later. 
+<br> - If you do not use Telerik products, remove the `Telerik.Licensing` NuGet reference from your project.|
+
 
 ## See Also