Xcode shows an error, but there is no error

Question

error: property 'airportIATA' not found on object of type 'Flight *' [3]

...
@interface Flight : NSManagedObject
@property (nonatomic, retain) NSString * airportIATA;
...

But this property exists. Is it any way to reset Xcode4?

Upd. It seems that Xcode began to use old .xcdatamodel, it shows also warnings like

Incompatible pointer types passing 'NSString *' to parameter of type 'Airport *'

But I changed property from Airport class to NSString two days ago.

Answer 1

OK, problem appeared because I had some old .h and .m files in a project folder, and new .h and .m with same names in a project subfolder.

For some reason Xcode compiler "forgot" that files I use in editor located at subfolder and started to use old ones.

I just replace old one with a new files.

Answer 2

Happended to me the other day. I just restarted Xcode and the errors went away. Try that, and also try restaring your mac.