Use UTF-8 strings. Sometimes +[NSString stringWithUTF8String:] returns nil (I have no idea why), so use an empty string in that case.

stepmania/src/arch/LoadingWindow/LoadingWindow_Cocoa.mm

@@ -55,7 +55,9 @@ void DisposeOfCocoaWindow()
 
 void SetCocoaWindowText(const char *s)
 {
-	[text setString:[NSString stringWithCString:s]];
+	NSString *str = [NSString stringWithUTF8String:s];
+	
+	[text setString:(str ? str : @"" )];
 	[text display];
 }