Exact Same Application Work in One Computer Doesn't Work in the Other

I and my friend have project files connected to dropbox. So code are the same.

Then, when I execute

NSEntityDescription *entity = [NSEntityDescription entityForName:@"Business" inManagedObjectContext:[BNUtilitiesQuick managedObjectCo开发者_StackOverflow中文版ntext]];

I got something. That same code set entity to nil in my friends' computer.

The BadgerNew.xcdatamodeld that's used to create the managedObject already changed. My team have reset the IPhone simulator and deleted the application from the IPhone simulator so that the whole thing is created new again. Doesn't work.

Not enough information to give a terribly useful answer.

However, DropBox is a horrible way to share a project. If you have multiple people working on the same codebase, then you should be using a revision control tool of some kind; svn and git being the most popular these days.

Grab the source from your friend's computer and drop it on your own. Then diff the two; opendiff MySource MyFriendsSource. See what differs. If nothing differs (unlikely), then there is something different in the configuration of your two machines.