How to reproduce
- Create Datasource that uses Json
- Configure a Elements Connect field with Root element and Json Columns
- Set Key field to the id value that does not exist in the columns
- Run configuration tester
- In the Configuration tester / Transformed JSON, we can see the evaluation results but NO error to indicate us that value used in the Key field is not correct
- In the Configuration tester / Table result Result set we can see only one (first) value. User can't understand why there is only one value here while in the Transformed JSON we have a list of values
- Do the same as if we set the wrong Key field value in the Local SQL datasource: show the message in the Transformed JSON to alert the user that the Key value is not correct.