█████ ██ ██ ██ █████ ██████ ██████ ██ ██ ██ ██ ██ ██ ██ ██ ██ ██ ██ ███████ ██ ██ ██ ███████ ██████ ██ ██ ██ ██ ██ ██ ██ ██ ██ ██ ██ ██ ██ ██ ██ ███████ ████ ██ ██ ██ ██ ██████
Started seeing "backup already in use" error from my daily Time Machine backups, against my Synology. Disabling and re-enabling AFP did the job (via Synology -> Control Panel -> Files Services -> Enable AFP service).
