doc: Update errors.md

docs/errors.md

@@ -5,7 +5,11 @@ nav_order: 19
 
 # Errors
 * **The reply URL specified in the request does not match the reply URLs configured for the application.**
-  * Please ensure that you have configured the internet URL on your Home Assistant network settings config and that you have added the correct redirect URI to your Azure app
+
+  or
+
+* **The provided value for the input parameter 'redirect_uri' is not valid.**
+  * Please ensure that you have configured the internet URL on your Home Assistant network settings config and that you have added the correct redirect URI to your Azure app as described in the [Prerequisites](./prerequisites.md)
 
 * **Client is public so neither 'client_assertion' nor 'client_secret' should be presented.**
   * Please ensure that you have set "Allow public client flows" to Yes in your Azure app under Authentication ![image](https://user-images.githubusercontent.com/36969394/198787952-9f818372-7684-42e1-ac30-a8ab05a5f478.png)