Hi,
Is your entity (from where comes the CreateOrUpdate) with Expose Read Only attribute as yes? Maybe is that the reason that you can have it in another modules. The is Function attribute is to use it in expressions, and it's not editable.
If you want to add that as a dependency to another module, you need to:
1) (Not the best solution, but faster) Chage the Exposed read only attribute to No, republish your producer module and then go to the consumer module and refresh your dependencies;
2) Create an Action inside the producer module (Normally called a wrapper) where you abstract your Create or Update business rules, where you use the entity CreateOrUpdate inside of it. then, make that action public and consume it in your consumer module.
Hope this can help.
Best regards,
Ricardo M Pereira