Hey @Daniele_Bulgarelli! Happy to help here. Just to double check, was your Retool instance working before? And how have you deployed Retool?
Usually this error means your license key is either incorrect or missing (thank you for sending those logs by the way) and this causes your license checks to fail (your Retool instance pings our servers every 6 hours to ensure that your license key is valid).
This can also happen if you have a trailing whitespace at the end of your license key (most common in Kubernetes deployments).