Cannot start app after update with Erlang 24

Thanks for the reply. I am not sure how to proceed and whether I interpreted your suggestion correctly. I compiled phoenix_pubsub with mix deps.compile phoenix_pubsub and now this dependency as reported by mix deps is

  • phoenix_pubsub 1.1.2 (Hex package) (mix)
    locked at 1.1.2 (phoenix_pubsub) 1f13f9f0
    ok

I still get the same error though when I run mix phx.server.