OperationNotFoundException when using a Scripting Automation chain in another chain

Say you have:

• An Automation Scripting chain called myJSOp, which has Document as input and output and just does return input
• And an Automation Chain that does the following (it's about login, mainly)

  - Context.FetchDocument
  - Log:
      level: warn
      message: "Before"
  - javascript.myJSOp
  - Log:
      level: warn
      message: "After"
  

Save, deploy, test. This leads to an error, OperationNotFoundException: No operation was bound on ID: javascript.myJSOp.

(The whole error is in attachment)