Unable to access frontend - 403: Forbidden

I have a remote Home Assistant node running on a Pi 4 and Home Assistant OS. It’s been there for months and I’ve never had an issue accessing it before.

Today, I’m getting a 403: forbidden error when I access port 8123 over http. I’ve tried from a private window in case it’s cookies; but no difference.

Luckily, I have access to the backend but can see nothing in the HA logs; apart from warnings about the version of HACS having deprecated behavior:

024-06-04 09:34:09.497 WARNING (MainThread) [homeassistant.helpers.frame] Detected that custom integration 'hacs' accesses hass.helpers.event. This is deprecated and will stop working in Home Assistant 2024.11, it should be updated to import functions used from event directly at custom_components/hacs/base.py, line 630: self.hass.helpers.event.async_track_time_interval(, please create a bug report at https://github.com/hacs/integration/issues

ha info shows

arch: aarch64
channel: stable
docker: 25.0.5
features:
- reboot
- shutdown
- services
- network
- hostname
- timedate
- os_agent
- haos
- resolved
- journal
- disk
- mount
hassos: "12.3"
homeassistant: 2024.5.4
hostname: scc
logging: info
machine: raspberrypi4-64
operating_system: Home Assistant OS 12.3
state: running
supervisor: 2024.05.1
supported: true
supported_arch:
- aarch64
- armv7
- armhf
timezone: Etc/GMT

I need to try and resolve this remotely as the node is some distance away in a remote location. There are local backups I can restore from but I’m loath to do this as I’ll lose sensor history - which is one of the main uses for this node.

Any suggestions? I’ve rebooted the pi but it made no difference: in fact, it only came up as far as observer and I had to start hassio_supervisor manually.

observer reckons everything is hunk-dory.

ANSWER: The IP address had been banned in ip_bans.yaml

I wandered off to get a coffee and the answer came to me: HA had banned the IP (for no apparent reason that I can determine).

Having SSH access I could edit /homeassistant/ip_bans.yaml and remove the entry. After doing ha core restart I could get back in.

Another reason to ensure you have backdoor access into a node.