Topic
Azure Guest users are unable to open SharePoint List Forms in SharePoint Online using the Nintex Automation Cloud app (also referred to as the SPFx app). A guest user may see the following issues in a SharePoint Online site:
-Unable to see the 'Nintex Automation Cloud' app in Site Contents.
-Unable to see the 'Nintex Automation Cloud' app in the ribbon on any SharePoint Online list.
-A published form fails to open when attempting to create a new list item.
-A published form fails to open when attempting to edit or view an existing list item.
Instructions
To grant read access to all users in the tenant, please follow all processes below.
Enable external sharing on the App Catalog site
- Navigate to https://tenantname-admin.sharepoint.com/
- Navigate to Sites > Active Sites.
- Search for 'appcatalog'.

- Select the 'AppCatalog' site in the search results.
- Select Settings.
- In the dropdown menu under 'External File Sharing', select 'New and existing guests' or 'Existing guests'.
- Select Save.

Enable the 'all users' claim via the SharePoint Online Management Shell
- Download and open the SharePoint Online Management Shell on your local machine.
- Run:
Connect-SPOService https://[tenantname]-admin.sharepoint.com - Enter credentials for a Global Administrator account.
- Run:
Set-SPOTenant -ShowAllUsersClaim $true- Note that -ShowAllUsersClaim must remain 'true'. Setting it to 'false' again may revert the permissions applied in the next process below.
Grant Read access to all users in the tenant
- Navigate to the App Catalog site permissions page at https://[tenantname].sharepoint.com/sites/AppCatalog/_layouts/15/user.aspx
- Select Grant Permissions.
- Type in 'All Users' until the suggestion appears; select 'All Users (membership)'.
- Select Show Options
- Uncheck the box for 'Send an email invitation'
- In the 'Select a permission level' dropdown menu, select Read.
- Select Share.

Additional Information
By default, the App Catalog site ([TenantURL]/sites/appcatalog) in a SharePoint Online tenant grants read access to 'Everyone except external users', which excludes Guest users. Granting Guest users read access to the App Catalog allows Guest users to see and use the Nintex Automation Cloud app in sites across the tenant (where site permissions allow).
The instructions above are intended to grant read access to all current and future users for the sake of ease in administration. However, if preferred, specific Guest accounts can be identified instead of using 'All Users (membership)'.
