When a Guest User goes to a page that contains a BindTuning web part (or any other third party web part), instead of seeing web part content, they may see a not-so-nice looking error message.
This could happen when Guest Users don’t have access to the Tenant App Catalog in which case they will get an "access denied" error when trying to access some of the web part’s resources within app catalogue’s ClientSideAssets directory.
This is a common occurrence with Guest Accounts as by default, they won’t have access to the Tenant App Catalog.
To get custom web parts to work for Guest Users, you need to perform the following actions.
- Grant guest users read permissions both to the tenant and to the site collection app catalogue.
- Turn on Microsoft’s public CDN (SharePoint public content delivery network). Why turn on Microsoft’s public CDN?
- For faster loading times. When the web part is loaded, the files are fetched from the most optimal location in relation to current end-user.
- To allow guest users to be able to use your web parts using a mobile browser. Even if you grant guests access to the app catalogue, they will still get an access denied error, when browsing the web parts using a mobile device.
A comprehensive article on this topic by Laura Kokkarinen is available here.