i m trying to extends all my documents with a new directory item (which looks like Subjects) and get rid of Coverage one.
so, i choose a custom dublincore schema that override default one, making a widget and extends the layout...but i get errors, almost everywhere.
Overriding dublincore is evil :)
Dublincore is the schema that store all the mandatory fields of Nuxeo Document. This is a standard schema, if you want to see a bit more on this point go there.
But that's not only for that. for maintenance of your code, if we update something on this part of our code, you will have to take care of our updates to push them into your code.
And last, but no least your error may happens because when you has overridden the schema you remove some fields but you didn't update the layout that wait for this field...
Anyway I hope, I convince you to not go to this way.
A better way is to:
To override the core type definition, I think you just have to do something like:
To override dublincore layout, you will have something like that:
I hope that will help you.