Steps to reproduce:

1. add action with args - modify https://github.com/atk4/data/blob/be7c84f9f8d125025761485c4b4f2d203fad545c/src/Model/UserActionsTrait.php#L153 action to make it non-system
2. open demos/data-action/jsactions2.php demo
3. click on Validate action
4. input some intent arg
5. click Next
6. click Validate
7. an exception is shown: