Core data application has encountered with an error

Hi,

I am running Mac X OS and I added new first core data application to learn how to develop applications for Mac OS but I got this following error message when I tried to start this application. What should I do now? I really need your help as soon as possible. Any suggestion would be greatly appreciated. Thanks.

Image may be NSFW.
Clik here to view.

The managed object model version used to open the persistent store is incompatible with the one that was used to create the persistent store.