Using OCL as fitness objective?

[LiBobb]

Hello,
I'm trying to use OCL as fitness objectives. However, the .momot file throws the error that it cannot find the instance file, which can be found if I use java function for fitness.

And I don't know if the braces are required. If I add the braces for the OCL string, the error changes to type mismatch since it expects the inner pattern to be a double.

Because the .momot file raise errors, no target class is generated in the src-gen, so it cannot be executed.
Could anyone offer me some help?
Thanks