text: Title: Warn if the client is instantiated with an outdated schema
  Body: ## Problem
  
  <!-- A clear and concise description of what the problem is. Ex. I'm always frustrated when [...] -->
  
  If this warning was present it would've made #180 easier for the user to solve by themselves.
  
  ## Suggested solution
  
  <!-- A clear and concise description of what you want to happen. -->
  
  Raise a warning if the client is instantiated using an out of date schema.