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

I'm using MS Windows 8.1 with Google Chrome Version 35.0.1916.114 m
I have a free Salesforce trial version

From the "My Name" menu I chose "Developer Console".
I get a new window Force.com Developer Console with the "Loading workspace ..." progress bar.
The progress bar gets hung at about 50%.

Any advice?

Oded