I just transferred my project between computers - from one running Xcode version 3.2.6 to one running version 4.6 (4H127). When running the program, I get a simple "Error loading" message. The main window appears to load ok visually, but everything is frozen. I can't even move the window. However, I can still access the main menu. The project compiles fine with no warnings. I am relatively new to Xcode 4. What could be causing this error? Let me know if I can provide any more information. (Since the error message is so terse, I can't think of any useful information.)