docs: add kb on typeerror-reading-options

knowledge-base/typeerror-cannot-read-properties-underfined-reading-options.md

@@ -0,0 +1,72 @@
+---
+title: TypeError Cannot read properties of undefined (reading 'options') in HTML5-based report viewers
+description: Learn how to resolve the TypeError about 'options' in HTML5-based report viewers.
+type: troubleshooting
+page_title: TypeError Cannot read properties of undefined (reading 'options') in HTML5-based report viewers
+meta_title: TypeError Cannot read properties of undefined (reading 'options') in HTML5-based report viewers
+slug: cannot-read-properties-of-undefined-reading-options
+tags: reporting, export, download, kendo ui, upgrade, options
+res_type: kb
+---
+
+## Environment
+
+<table>
+    <tbody>
+        <tr>
+            <td> Product </td>
+            <td> Reporting </td>
+        </tr>
+        <tr>
+            <td> Version </td>
+            <td> 19.1.25.521+ </td>
+        </tr>
+    </tbody>
+</table>
+
+## Description
+
+After updating Telerik Reporting from version `19.0.25.313` to `19.1.25.521`, the export functionality (for example, downloading to Excel) no longer works. The button fails to initiate the download, and there is a `TypeError: Cannot read properties of undefined (reading 'options')` error in the browser console. The initial REST service responses are successful, suggesting a frontend issue.
+
+## Cause
+
+The issue likely occurs due to an incompatibility between the report viewer and the [Kendo UI for jQuery](https://www.telerik.com/kendo-jquery-ui) version referenced on the page. For example, Reporting version (`19.1.25.521`) is built against Kendo UI for jQuery version `2025.1.227`, while an older Kendo UI version may cause client-side errors.
+
+## Solution
+
+### Step 1: Check Current Kendo UI Version
+
+1. Open the browser console on the page containing the report viewer.
+1. Execute the following command:
+
+	````javascript
+kendo.version
+````
+
+
+### Step 2: Determine Required Kendo UI Version
+
+1. Visit the [Telerik Reporting Release History](https://www.telerik.com/support/whats-new/reporting/release-history) page.
+1. Locate your current Reporting version and open the corresponding page.
+1. Check the compatible Kendo UI for jQuery version listed in the release notes.
+1. If the Kendo UI version matches the required version for your Reporting release, continue with [Further Steps](#further-steps). If there is a mismatch, follow [step 3](#step-3-choose-a-resolution-method) to resolve the compatibility issue.
+
+### Step 3: Choose a Resolution Method
+
+#### Option A: Update Kendo UI for jQuery
+
+Update your Kendo UI for jQuery reference to the compatible version based on the [step 1](#step-1-check-current-kendo-ui-version) and [step 2](#step-2-determine-required-kendo-ui-version).
+
+#### Option B: Use Telerik Reporting's Kendo UI Subset
+
+If your page does not use other Kendo UI components, replace the Kendo UI script reference with the subset provided by the Reporting REST service:
+
+````html
+	<script src="api/reports/resources/js/telerikReportViewer-kendo"></script>
+````
+
+>note This approach ensures compatibility when the report viewer and Reporting REST service versions match.
+
+## Further Steps
+
+If you continue to experience issues after verifying the Kendo UI version, consider [capturing a HAR file](https://support.google.com/admanager/answer/10358597?hl=en#capture-your-http-network-session) using your browser's DevTools. Then, attach this file to a support ticket via the [Telerik Reporting support system](https://www.telerik.com/account/support-center/contact-us/technical-support). This will help the support team review the JavaScript files requested by your application and provide more targeted assistance.