I am on v1.2 and Core. If I used cli to register a flow from a python script to a remote server it seems to work (except it ignores the scheduler). But when I use flow.register from within the code it gives an error. Graphql validation fails unknown type “register_tasks_input”. Any idea what I am doing wrong?

Could you share the code you're using that leads to this error? Can you share the output of prefect diagnostics?

What is the version of your server?