When I use Application Loader, I get to the point where it asks me to \"Choose...\" the file to be uploaded.
If I understand correctly, it supposes to be the appName.app
Go and login to the iOS Provisioning Portal. From the menu on the left, select "Distribution" and you should be landed to the "Prepare App" tab. Read through the instructions carefully, you mostly need the information under "Building your Application with Xcode for Distribution". Remember that "Only Team Agents are authorized to prepare and submit applications for distribution".
If I remember correctly, the file that you need to choose is a "*.ipa" file which I was able to generated by archiving to project.
If you have xcode 4 it is recommended to add another scheme e.g. dist scheme and configure the scheme to release. Than compile (using the dist scheme) and go to the organizer to view/share/ or submit the application.
If you are using xcode 4, it has a bug which crashes the xcode if you choose validate or submit, in this case you should save upload the *.ipa using the application loader.
Hope this helps.
Download the latest Application loader from here: https://itunesconnect.apple.com/apploader/ApplicationLoader_3.1.dmg. (Download the latest one. This doesn't get updated automatically. If you haven;t downloaded this recetnly you probably have a older version that may have errors which are solved in the newer version)
Then 1) Archive your build. 2) After your build archives, you will be in the builds page. 3) Export that build 4) Click "App Store blablabla" row 5) Save the file somewhere 6) Open Application Loader 7) click upload 8) upload that saved file.
Done.
I fixed this issue simply by renaming the storyboard file for the iPhone storyboard to Main_iPhone.storyboard.
Xcode looks for this file because it's built in to your plist (property list) file when you create a new project.
I created a universal app, and somewhere along the way I renamed that storyboard file. Because my app is universal, I didn't want to go monkeying around with deleting plist keys.
After trying again, I got the same error. Then I quit Xcode, restarted, re-validated, and it worked.
Good luck.
This is basically it. Hope it will help anyone looking for the answer.