Always check that you have (by accident) activated the OCPP function. If you have done so and want to use this function, make sure you are an active member of the configured OCPP network. If your membership to an OCPP service is not active, you will be able to start loading but it will stop after a few seconds.

So always check if you have activated this OCPP feature, if you want to use it AND if you have a valid account (correct login credentials / membership) with your OCPP service.