When creating a save button in a task form, the button cannot be used without one of the task outcomes being selected.
This is expected behavior. As a workaround, try the following:
- Create an additional outcome (Incomplete or In Progress etc).
- Set the new outcome as the default value for the outcome control
- Create a hide / disable rule on the 'Save & Submit' button for when the outcome is equal to the value created earlier. For example: taskoutcome=="Incomplete"
- This would allow the save button to be used, but would prevent anyone from submitting the form until the outcome field has been set to one of the expected out of the box fields