docs(common): KB on missing CDN for JS interop

_contentTemplates/common/js-interop-file.md

@@ -25,6 +25,5 @@
           <script src="_content/telerikuiforblazor/js/telerik-blazor.js" defer></script>
         </head>
 
-    As of version `1.2.0` we no longer maintain a CDN with the JS Interop file. If you would like to serve it from a cloud, save its contents and create a CDN of your choice.
 #end
 

knowledge-base/no-cdn-for-js-interop-file-1-2-0-and-later.md

@@ -0,0 +1,33 @@
+---
+title: No CDN for JS Interop after 1.2.0
+description: How to include the JS Interop file after 1.2.0 when there is no CDN.
+type: how-to
+page_title: No CDN for JS Interop after 1.2.0
+slug: no-cdn-for-js-interop-file-1-2-0-and-later
+position: 
+tags: 
+ticketid: 
+res_type: kb
+---
+
+## Problem
+
+I cannot find the CDN for the `telerik-blazor.min.js` JS Interop file. I get `404` requests when I try to use it for version `1.2.0` or later.
+
+```
+GET https://kendo.cdn.telerik.com/blazor/1.2.0/telerik-blazor.min.js net::ERR_ABORTED 404
+```
+
+Other symtoms can include:
+* JS errors shown in the browser console such as `Error: Microsoft.JSInterop.JSException: Could not find 'TelerikBlazorDatePicker' in 'window'`.
+* inputs that do not work or validate as expected
+* inability to expand a date picker
+* inability to navigate between views
+
+## Solution
+
+As of the `1.2.0` release, the JS Interop file is no longer maintained on the Telerik CDN. As of Preview 6, the .NET framework provides a feature for inclusion of local assets coming from a package like ours, and this is how we distribute the file.
+
+@[template](/_contentTemplates/common/js-interop-file.md#js-interop-file-snippet)
+
+If you would like to serve it from a cloud, save its contents and create a CDN of your choice.