No matches for kind "Middleware" in version "traefik.containo.us/v1alpha1"

After upgrading traefik from version 2.2.0 to 2.2.1 I got the following errors when deploying my middleware componentss

Example:

apiVersion: traefik.containo.us/v1alpha1
kind: Middleware
metadata:
  name: https-redirect
spec:
  redirectScheme:
    scheme: https
    permanent: true
    port: 443

Error Message:

unable to recognize "management/traefik/004-middleware.yaml": no matches for kind "Middleware" in version "traefik.containo.us/v1alpha1"

What is the correct apiVersion to use? Why is this version chanaging and where can I found a information which versions are valid?

Thanks for any hints.

===
Ralph