Error on performing any Process related action with anonymous access

Process related tasks are not supported with anonymous access. If you try to access any process related tasks (for example, Start Process/Perform Task) from a web or mobile app having anonymous access, you might run into this error.

{ "type": "vbcs://process_service_problem", "title": "Process Service Error", "detail": "Authorization failed.", "status": 500, "o:errorCode": "authorizationFailed" }

This will happen even if you manually allow anonymous access and give anonymous access credentials to the Process Applications backend.