iOS5 Storyboard error: Storyboards are unavailable on iOS 4.3 and prior

I've built a small app using storyboards and it ran great. Just before final testing I decided to try it out to see if it runs on iOS 4.3. I clicked on the gray 5.0 in the project settings and selected 4.3.

The app failed to build with the following error message:

Storyboards are unavailable on iOS 4.3 and prior

Both the iPhone and iPad storyboards tell me that.

The issue that when I switched back to iOS5 target, I still keep getting these errors from both storyboards, and the product won't build! I checked: iOS Deployment target in projects settings is 5.0 Target app deployment target is 5.0 Build settings uses iOS 5.0 SDK

What else do I need to do to restore my project to a buildable state? Is this a brand new bug or am I forgetting something?

Update: I kept getting this error even after doing a clean. I changed the debugger in Schemes to "LLDB" and did an additional clean, the project now builds and compiles

I also got this problem and finally I solved this by following procedure:

1. Open XXXXXX.storyboard
2. Open Identity and Type tab in your right view of Xcode.
3. Set the value of Development in Document Versioning to "Xcode 4.2" (my default value is "Default Version (Xcode 4.1)".
4. Change the value of Deployment from Project SDK Version (iOS 5.0) to iOS 5.0, then back to Project SDK Version (iOS 5.0)

Rebuild the project and the error should be resolved.

The solution that worked for me was just to delete the ~/Library/Developer/Xcode/DerivedData directory for my project.

I'm just going to add this one as another possible answer here, as the first solutions worked for me several times (as I mentioned in my previous comment) until today when I couldn't get my project to compile for love nor money with the same error. With the debugger changed and Xcode set to 4.2 and restarting several times I could not compile. However I discovered another way to get around this issue.

Select the storyboard in the left column and 'Show in Finder' and drag the storyboard to the desktop. Xcode will now change its colour to red and be unable to compile.

Clean the project, drag the storyboard back from the desktop to the directory in finder.

Then, it builds and the error goes away again.

I don't know what triggered the error originally as I'm developing under iOS5 and building for 4.3, but it seems to come up from time to time and.