App Store upload. Problem with SDK

I just tried to upload a completed app via iTunes Connect, and I received the following error:

The binary you uploaded was invalid. Apple is not currently accepting applications built with this version of the SDK.

I upgraded to the 4.0 SDK. I got this same exact error with the PREVIOUS version of the SDK as well. 3.?.? (whatever it was). Now in Xcode, I no longer have the option to select a previous version of t开发者_运维技巧he SDK.

Any suggestions?

you must download "Application Loader."

1. Make sure when you build the .app bundle for distribution, that you are building for "Device" and "Distribution" in the drop down menu of the main XCode screen.
2. Make sure in the "Project Settings" that you have set the base SDK to 4.0 and your deployment target SDK to 3.0 (or whatever you want it to be).. both settings are found in that "Build" menu. Settings are for the "Distribution" configuration

This will build the app with the latest SDK but allow users of 3.0 (or whatever you chose) to use the app so long as you only included API that was available in 3.0 or below.