Firewalld fails to start with error message internal:0:0-0: Error: No such file or directory

Issue

• firewalld fails to start. The file /var/log/firewalld shows the following error message:

  ERROR: COMMAND_FAILED: 'python-nftables' failed: internal:0:0-0: Error: No such file or directory
  

• firewalld fails to start. The file /var/log/firewalld shows the following error message:

  ERROR: COMMAND_FAILED: 'python-nftables' failed: internal:0:0-0: Error: Set member cannot be prefix, missing interval flag on declaration
  

• After adding permanent entries to a ipset via firewall-cmd, running firewall-cmd --reload or systemctl restart firewalld doesn't work anymore and firewall rules are not loaded.