xcdatamodeld no xcdatamodel visible

Question

I am working in xcode5. The project I have contains ProjectName.xcdatamodel. I now want to sustain upgrade to the project I have. When I tried to Add Version Model, I can see in packet ProjectName.xcdatamodeld. When I click on this, I don't see any xcdatamodel or any fields. It seems that xcode does not open the packet. How to solve this?

1. I've tried to delete the reference and add the file again + restart xcode - but no success
2. I've also tried to manually add in pbxproj the currentVersion, under XCVersionGroup, because there is no current version, but still with no success.
3. I ve also tried to change the path under XCVersionGroup, because ProjectName.xcdatamodeld is under ../ProjectName.xcdatamodeld from where the file .pbxproj is open, but still no success.

Here is how the XCVersionGroup looks after I add a version model to ProjectName.xcdatamodel:

/* Begin XCVersionGroup section */
                D3532BF31910E7490046D71B /* ProjectName.xcdatamodeld */ = {
                        isa = XCVersionGroup;
                        children = (
                        );
                        name = ProjectName.xcdatamodeld;
                        path = ../../ProjectName.xcdatamodeld;
                        sourceTree = "<group>";
                        versionGroupType = wrapper.xcdatamodel;
                };
/* End XCVersionGroup section */

Answer 1

I managed to solve the issue by Adding "Add version model" to the main project, and NOT to a folder inside the main project.