error: class :: takes type parameters

[paulpaul1076]

I define a Reads object like so:
val reestrdocReads = Jsonx.formatAuto[Reestrdoc]
but when I compile my code, I get this error, which points me to the definition of my Reads object:
error: class :: takes type parameters.

The "::" thing is a list I assume.

I do have a field in one of my case classes that is defined like so: tc_goods: ::[TcGoodsTtnoutEgais].

What is the issue here?