Mozilla/5.0 (Macintosh; Intel Mac OS X 10.9; rv:28.0) Gecko/20100101 Firefox/28.0 Mozilla/5.0 (X11; Linux i686; rv:28.0) Gecko/20100101 Firefox/28.0 Mozilla/5.0 (Windows NT 6.1; WOW64; rv:28.0) Gecko/20100101 Firefox/28.0 Reproduced on latest Aurora (20131212004008). Steps to reproduce: 1. Open App Manager 2. Add a packaged app 3. On the Manifest Editor area, select the "+" button to add a new value for a property - a field to enter it's name is open 4. Click outside the text field or select anything outside Firefox window 5. Return to the value to complete it Actual results: If a value is not supplied the first time, it cannot be edited later. ":" remains on the screen and it can only be deleted. Expected results: The empty fields can be edited later.
This code will be removed soon: bug 1007061.