Steps to reproduce

• Deploy a case with a human task and a referenced embedded form
  • camunda:formKey="embedded:deployment:forms/simple-form.html"
• Open Tasklist and navigate to the task

Expected behavior
The embedded form is shown

Observed behavior
The following error message is shown: "Form failure: deploymentId is null"

Hints

• See the failing engine test case
• The REST API endpoint GET /task/$ID/deployed-form returns with status code 400:

  {"type":"InvalidRequestException","message":"deploymentId is null"}
  

• The endpoint is based on FormService#getDeployedTaskForm