CoreData warning: Unrecognized optimized model archive format

When running my iOS program on an iPad, the console gives the following error when opening the CoreData data store:

CoreData warning: Unrecognized optimized model archive format
Failed to load optimized model: Error Domain=NSCocoaErrorDomain Code=134060 "The operat开发者_如何学Goion couldn’t be completed. (Cocoa error 134060.)" UserInfo=0x150160 {Root cause=Unknown archive format}

Anyone got any ideas what this means? and how to fix?

Thanks. Glen.

It's always hard to say whether or not this was the fix, because it seems that what works for some people in Xcode doesn't work for others, but the way I finally got rid of this error was by cleaning the project and rebuilding.

Prior to that, I tried to delete the app and run the project again (without cleaning), but that still generated the error, so I think it just has to do with a cached model in the build folder that's messing up its ability to "load the optimized model".

Hope this helps!