I found docker wouldn’t start for me on my Buster desktop.
journalctl -u docker -f showed :
Aug 15 09:35:50 walnut dockerd[28612]: failed to start daemon: Error initializing network controller: error obtaining controller instance: failed to create NAT chain DOCKER: iptables failed: iptables -t nat -N DOCKER: iptables v1.8.2 (nf_tables): CHAIN_ADD failed (No such file or
Aug 15 09:35:50 walnut dockerd[28612]: (exit status 4)
Fixing, yet again, seems a case of replacing nft/nftables stuff with the legacy iptables counterparts –
update-alternatives --set ip6tables /usr/sbin/ip6tables-legacy
update-alternatives --set iptables /usr/sbin/iptables-legacy