Sometimes, people tend to click the wrong button or get confused about the procedure. Hence, the problem of the app admin being deleted may arise. To rectify the problem of the Google Workspace or G Suite administrator who has installed Shared Contacts for Gmail™ that was deleted or downgraded to a non-super admin role, follow these steps.
In case of the deletion of an admin, make sure you first transfer ownership of all the shared contact labels they own.
Time needed: 2 minutes
Follow the steps below to reactivate Shared Contacts for Gmail™ for administrators:
To do this, go to the Google Workspace Marketplace, then click on the “Domain Install” button. Follow all the prompts until confirmation of the reinstallation. 
In the left-hand menu, navigate to Settings > Users & Licenses.

This confirms that the app is functioning properly for each collaborator.
If any collaborators show a “Revoked” status, the new Super Admin should:


Well done for resolving the issue regarding the app admin being deleted! You can now resume sharing your labels with ease.
If it still doesn’t work after this, contact support.