The local storage server cannot be deleted
Admin delete of the built-in local storage server returned 400.
Why this happens
Local server is required for the site and is protected. Same family as The local storage server is protected.
Diagnose and fix
1. Do not delete local — manage disk/caps instead (Manage the local storage server).
2. Add remote/CDN servers for scale-out; leave local in place.
3. Soft-delete/trash rules also block destructive local actions.
4. See Server trash, restore, purge for non-local servers.