Strange error after server reboot

I got
FATA[22-03-2023 13:48:55] Unable to list alerts : performing request: Get "": http code 404, invalid body: invalid character '<' looking for beginning of value

System is

Any clues?

It seems that another service may already be using port 8080 (default crowdsec installation port) if so you can alter the configuration to use a different port. You can update /etc/crowdsec/config.yaml also you must update /etc/crowdsec/local_api_credentials.yaml to the same port.