Working the "Handle Actions with Controllers" trailhead module and I'm not getting past the validation.
If I put the component in a test jig, I can see the button function and set the check box as expected.
 

Here is the code I'm using to set the item as packed...

component.set("v.item.Packed__c", true );

I'm assuming the validator does not like my syntax. Can you give me a hint to get past this?

Thanks.
John