Xcode Build Succeeded but not run on iPhone [duplicate]

Question

Possible Duplicate:
Is it possible to target older iOS versions when using Xcode 4.2 and iOS 5 SDK?

I have a problem that i don't really understood, i'm using Xcode till yesterday and all work perfect, but yesterday i install Xcode 4.2 with iOS 5, but now when I try to do a run with my iPhone set as target is successfully build the application and then Stop immediately. No Errors, nothing in console logs. The application doesn't even copy over to my device. Xcode says: Building, Running, Finished Running....all within 2 seconds... On the simulator all works, but on the device nothing happen.

i have xCode 4.2 with iOS 5, and i have an iPhone 3G with io 4.2.1 and under the Deployment target i choose 4.2 like last day. Please help me i'm going crazy!

i see on the organizer window of Xcode, that the log give me this result, i copy a small part:

Sat Oct 15 18:17:14 unknown lockdownd[18] <Error>: 2ff68000 handle_connection: Could not receive USB message #6 from Xcode. Killing connection
Sat Oct 15 18:17:14 unknown com.apple.mobile.lockdown[18] <Notice>: Could not receive size of message
Sat Oct 15 18:17:14 unknown com.apple.mobile.lockdown[18] <Notice>: Could not receive size of message
Sat Oct 15 18:17:14 unknown lockdownd[18] <Error>: 2ff68000 handle_connection: Could not receive USB message #6 from Xcode. Killing connection
Sat Oct 15 18:17:15 unknown com.apple.mobile.lockdown[18] <Notice>: Could not receive size of message
Sat Oct 15 18:17:15 unknown lockdownd[18] <Error>: 2ff68000 handle_connection: Could not receive USB message #6 from Xcode. Killing connection
Sat Oct 15 18:17:16 unknown lockdownd[18] <Error>: 2ff68000 handle_connection: Could not receive USB message #6 from Xcode. Killing connection
Sat Oct 15 18:17:16 unknown com.apple.mobile.lockdown[18] <Notice>: Could not receive size of message
Sat Oct 15 18:17:16 unknown com.apple.mobile.lockdown[18] <Notice>: Could not receive size of message
Sat Oct 15 18:17:16 unknown lockdownd[18] <Error>: 2ff68000 handle_connection: Could not receive USB message #6 from Xcode. Killing connection
Sat Oct 15 18:17:17 unknown lockdownd[18] <Error>: 2ff68000 handle_connection: Could not receive USB message #6 from Xcode. Killing connection
Sat Oct 15 18:17:17 unknown com.apple.mobile.lockdown[18] <Notice>: Could not receive size of message
Sat Oct 15 18:17:17 unknown lockdownd[18] <Error>: 2ff68000 handle_connection: Could not receive USB message #6 from Xcode. Killing connection
Sat Oct 15 18:17:17 unknown com.apple.mobile.lockdown[18] <Notice>: Could not receive size of message
Sat Oct 15 18:17:18 unknown lockdownd[18] <Error>: 2ff68000 handle_connection: Could not receive USB message #6 from Xcode. Killing connection
Sat Oct 15 18:17:18 unknown com.apple.mobile.lockdown[18] <Notice>: Could not receive size of message
Sat Oct 15 18:17:18 unknown com.apple.mobile.lockdown[18] <Notice>: Could not receive size of message
Sat Oct 15 18:17:18 unknown lockdownd[18] <Error>: 2ff68000 handle_connection: Could not receive USB message #6 from Xcode. Killing

What is the problem?

P.S. i try to put the architecture to armv6 and build on the device is that the problem?...but how it's changed?...i have never changed the architecture on Xcode.

Answer 1

you are right - the problem is probably that the 3G runs an amrv6 and you are only building for armv7

in your build settings you find a setting for valid architectures. There should be one entry called armv7

just add another entry armv6 to that setting. that should do the trick