3342103 - Key User Extensibility apps are not available or read only - SAP S/4HANA Cloud Public Edition

You're getting one of the following issues while trying to use any of the apps for Key User Extensibility (i.e. Custom CDS Views, Custom Fields, Custom Analytical Queries, Custom Logic):

• "Create/Edit/Delete/New" buttons are disabled or missing.
• Error message "Application can only be used in the Extensibility Development System" in "Extensibility Inventory" app.
• Error message "Items of type XXX must not be edited in this tenant".
• Error message "Items of type Custom Field must not be edited in this tenant" in Custom fields app.
• Error message "Items of type Custom Reuse Library must not be edited in this tenant" in "Custom Reusable Elements" app.
• Error message "Extensibility is not active. Use the customizing tenant instead".
• Error message "Not able to load the query name prefix or the package name. Adaptation Transport Organizer (ATO) is not configured for this system" in Custom analytical queries app.
• Error message "The application is not configured. Find details in SAP Note 2283716".
• Error message "Application not configured. Use Extensibility Test tenant".
• Error message "Not Authorized to create Business logic extension" when trying to create a Custom Logic.

SAP S/4HANA Cloud Public Edition

Application, Extensibility, Development System, Extensibility Inventory, must not be edited in this tenant, Custom fields, Custom Reusable Elements, extensibility is not active, customizing tenant, Adaptation Transport Organizer, ATO, is not configured for this system, custom analytical queries, custom cds views, buttons , KBA , BC-SRV-APS-EXT-SL , Manage and Import Software Collections , BC-SRV-APS-EXT-FLD , Custom Fields , BC-SRV-APS-GKE , Generic CDS Key User Editor , BC-SRV-APS-EXT-BO , Custom Tables and Nodes , BC-SRV-APS-IAM , Identity and Access Management , BC-SRV-APS-EXT-BL , Custom Business Logic , BC-SRV-APS-EXT-AQD , Fiori based Query Designer , Problem