MonoMac: and Xcode 4.0 error: “Unknown Window class MainWindow in Interface Builder file”

Question

I've created a new MonoMac project and opened the MainWindow.xib with Interface Builder (Xcode). After doing a simple change (renamed Window title), the project can't be built anymore. Does anyone know how to fix this?

I'm using MonoDevelop 2.6, MonoFramework-2.10.1 with Xcode 4.0 on OS X 10.6.7.

This is the error message:

2011-03-28 18:45:39.986 HelloWorld[30332:613] Unknown Window class MainWindow in Interface Builder file, creating generic Window instead

Unhandled Exception: System.InvalidCastException: Cannot cast from source type to destination type. at HelloWorld.MainWindowController.get_Window () <0x0002e> at HelloWorld.AppDelegate.FinishedLaunching (MonoMac.Foundation.NSObject) <0x0003d> at (wrapper dynamic-method) object.[HelloWorld.AppDelegate.Void FinishedLaunching(MonoMac.Foundation.NSObject)] (MonoMac.Foundation.NSObject,MonoMac.ObjCRuntime.Selector,MonoMac.Foundation.NSObject) <0x00033> at (wrapper native-to-managed) object.[HelloWorld.AppDelegate.Void FinishedLaunching(MonoMac.Foundation.NSObject)] (MonoMac.Foundation.NSObject,MonoMac.ObjCRuntime.Selector,MonoMac.Foundation.NSObject) <0x000eb> at (wrapper managed-to-native) MonoMac.AppKit.NSApplication.NSApplicationMain (int,string[]) <0x00003> at MonoMac.AppKit.NSApplication.Main (string[]) <0x00017> at HelloWorld.MainClass.Main (string[]) <0x00019>

Thanks for any help.

Cheers

PS: I found a troubleshooting help on http://monotouch.net/Documentation/Troubleshoot#Unknown_class_XXXX_in_Interface_Builder_filebut I guess it doesn't count in this case, since the class MainWindow already exists by default..

Answer 1

I think I've found the answer: http://go-mono.com/forums/#nabble-td3390853

Xcode 4.0 is not really supported right now.. but I hope someone else corrects me :-)

Answer 2

This post contains the explanation about the incomplete support of Xcode 4.0. It is recommended to use Xcode 3.2.6 until Xcode 4.0 is supported.