This error occurs because the field 'value' is private to the module 'dif_module::contract'. In Rust, struct fields are private by default, meaning they can only be accessed within the same module they are defined in. To resolve this, you can define a public getter function within the 'dif_module::contract' module that returns the value you need. This allows other modules to call this function and access the field indirectly.

Another way to fix this is to change the visibility of the field itself to public if it is safe and appropriate to do so. However, often defining a public getter method is a better practice as it provides more control over how the field value is accessed and manipulated.