can't log in itunes producer

Hello.

I can't log in to itunes producer in OSX el capitan.

It has always worked well, but for two days not working.
I Introduce the ID and password and the login screen appears again. It's the same with other Apple ID. And it's the same on another Mac OSX Mavericks.
Does anyone comes up with what's going on? The Apple technical support has failed to solve.
Thank you.