Steps to reproduce:

1. Deploy a process containing an external task with topic name "foo"
2. Start an instance of that process
3. Fetch and lock the external task

   POST /external-task/fetchAndLock
   
   {
     "workerId": "abc",
     "maxTasks": 2,
     "topics": [
       {
         "topicName": "foo",
         "lockDuration": 100000
       }
     ]
   }
   

4. Submit a failure

   POST /external-task/<external-task-id>/failure
   
   {
     "workerId": "abc",
     "errorMessage": "Does not compute",
     "errorDetails": "{\"foo\":\"bar\"}",
     "retries": 0,
     "retryTimeout": 60000
   }
   

Expected behavior:

• When opening the incident error details in Cockpit, the error details are shown accordingly.

Observed behavior:

• The error details shows [object Object]:
  

Hints:

• The REST API returns the error details as text/plain
  
• But AngularJS does a default transformation to JSON: https://docs.angularjs.org/api/ng/service/$http

  If the Content-Type is application/json or the response looks like JSON, deserialize it using a JSON parser.