Mapping Model nowhere to be found (Cocoa Error 134140)

Basically, I have a Versioned xcdatamodel and I am migrating from V2 to V3

I created a Mapping Model with a custom policy.

Once the PersistenStoreCoordinator tries to do its job, I hit a Cocoa Error No. 134140 (can't find mapping model for migration)

This Question basically is the same one I'm having but I am using Xcode 4.6.3

Things I have tried:

Forcing the xcmappingmodel to reside inside the xcdatamodelId and ensuring my mapping model is not 0kb in size as per the answer of this question
Removing the xcdatamodelId references from Xcode and adding them back (answer of this question)
Clean and Clean Build Folder options

EDIT Here are my debug statements if anyone is interested...

Handling DB Upgrade
sourceMetadata is {
NSPersistenceFrameworkVersion = 419;
NSStoreModelVersionHashes =     {
    OriginalPicture = <ce8de6ad c694b569 dcc1d706 d4df3928 05052cab 14a092f1 340cbf01 2306e861>;
    PanoramicInfo = <923298fa 0af16c01 d5ba91ca 19c6252c 8adee68a bfe7b86b 75285500 6883a1aa>;
};
NSStoreModelVersionHashesVersion = 3;
NSStoreModelVersionIdentifiers =     (
    ""
);
NSStoreType = SQLite;
NSStoreUUID = "F83640F3-8686-438F-97CC-48311EB74B9C";
"_NSAutoVacuumLevel" = 2;
}

Not Compatible Models Migration is NEEDED!
SourceEntity: OriginalPicture: <ce8de6ad c694b569 dcc1d706 d4df3928 05052cab 14a092f1 340cbf01 2306e861>
DestinationEntity: OriginalPicture: <ce8de6ad c694b569 dcc1d706 d4df3928 05052cab 14a092f1 340cbf01 2306e861>
SourceEntity: PanoramicInfo: <923298fa 0af16c01 d5ba91ca 19c6252c 8adee68a bfe7b86b 75285500 6883a1aa>
DestinationEntity: PanoramicInfo: <1d7836cd f3ccf5fa 487c1984 e2b3f46c abc3b706 c06512d5 0bac698c a5d8cb20>
The operation couldn’t be completed. (Cocoa error 134140.)

Second EDIT

I've been trying to get the Mapping Model directly by using:

NSURL *fileURL = [[NSBundle mainBundle] URLForResource:@"Update23Model" withExtension:@"cdm"];

But strangely fileURL points to nil.....

How do you add the mapping model to the bundle then?

Solution

Looks like an Xcode 4.6.3 bug... The xcmappingmodel must not be inside any group folder it seems....

When I created it at the root level of the xcode project, the mapping was found by the IDE.