could not change executable permissions on the application.

I could solve it erasing an application that I had previously uploaded using the same Bundle Identifier (xcode get's confused doing the chmod).

Try checking the log from xCode Organizer (Your device's Name -> Console) you should get information from that log.

because i already have the same app using the same bundle identifier installed on the phone.

- what you need to do is to delete all those apps on your iphone which is using the same bundle identifier name