As has been mentioned on here several times. On my system the updates in the last week a have resulted in pihole-FTL not starting.
Only solution has been to rename the
sudo pihole status
[✗] DNS service is NOT running
sudo mv /etc/pihole/pihole-FTL.db /etc/pihole/pihole-FTL-old.db
systemctl restart pihole-FTL.service
sudo systemctl status pihole-FTL.service
● pihole-FTL.service - Pi-hole FTL
Loaded: loaded (/etc/systemd/system/pihole-FTL.service; enabled; preset: enabled)
Active: active (running) since Tue 2025-06-03 09:30:30 BST; 7s ago
Process: 2910812 ExecStartPre=/opt/pihole/pihole-FTL-prestart.sh (code=exited, status=0/SUCCES>
Main PID: 2910826 (pihole-FTL)
Tasks: 7 (limit: 9277)
Memory: 4.5M (peak: 5.0M)
CPU: 204ms
CGroup: /system.slice/pihole-FTL.service
└─2910826 /usr/bin/pihole-FTL -f
Jun 03 09:30:30 duo pihole-FTL[2910826]: 2025-06-03 09:30:30.266 BST [2910826M] INFO: FTL user: pi>
Jun 03 09:30:30 duo pihole-FTL[2910826]: 2025-06-03 09:30:30.266 BST [2910826M] INFO: Compiled for>
Jun 03 09:30:30 duo pihole-FTL[2910826]: 2025-06-03 09:30:30.269 BST [2910826M] INFO: Wrote config>
Jun 03 09:30:30 duo pihole-FTL[2910826]: 2025-06-03 09:30:30.269 BST [2910826M] INFO: - 155 total>
Jun 03 09:30:30 duo pihole-FTL[2910826]: 2025-06-03 09:30:30.269 BST [2910826M] INFO: - 144 entri>
Jun 03 09:30:30 duo pihole-FTL[2910826]: 2025-06-03 09:30:30.269 BST [2910826M] INFO: - 11 entrie>
Jun 03 09:30:30 duo pihole-FTL[2910826]: 2025-06-03 09:30:30.269 BST [2910826M] INFO: - 0 entries>
Jun 03 09:30:30 duo pihole-FTL[2910826]: 2025-06-03 09:30:30.270 BST [2910826M] INFO: Parsed confi>
Jun 03 09:30:30 duo pihole-FTL[2910826]: 2025-06-03 09:30:30.270 BST [2910826M] INFO: PID file doe>
Jun 03 09:30:30 duo pihole-FTL[2910826]: 2025-06-03 09:30:30.270 BST [2910826M] INFO: