Building app for MacStore - productbuild error 'NSInvalidArgumentException'

Hello,
I’m having some trouble creating the package that needs to be submitted to the MacStore. I followed the steps found on the forums, from here http://forum.unity3d.com/threads/71340-Submit-Unity-games-to-the-Mac-App-Store! and here http://technology.blurst.com/unity-games-and-mac-app-store/

But when I get to the point:
productbuild --component “/path/to/Your Game.app” “/Applications” --sign “3rd Party Mac Developer Installer: Flashbang Studios, LLC” “/path/to/output/game.pkg”
I will get the following error message in the terminal:

*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*** -[NSCFDictionary setObject:forKey:]: attempt to insert nil key'
*** Call stack at first throw:
(
	0   CoreFoundation                      0x00007fff857db784 __exceptionPreprocess + 180
	1   libobjc.A.dylib                     0x00007fff849b5f03 objc_exception_throw + 45
	2   CoreFoundation                      0x00007fff857db5a7 +[NSException raise:format:arguments:] + 103
	3   CoreFoundation                      0x00007fff857db534 +[NSException raise:format:] + 148
	4   Foundation                          0x00007fff87d04caf -[NSCFDictionary setObject:forKey:] + 164
	5   productbuild                        0x0000000100001f4c createDistributionAndComponentPackages + 1465
	6   productbuild                        0x0000000100002b55 main + 2012
	7   productbuild                        0x0000000100001834 start + 52
	8   ???                                 0x0000000000000007 0x0 + 7
)
terminate called after throwing an instance of 'NSException'
Abort trap

Anyone has any idea what could be the problem? I double checked the plist file, but I couldn’t find anything (nothing I changed solved the problem).

Thanks in advance.

Gizella

Did you ever figure this one out?