Offer button does not appear

I want to negotiate for a player but there isn't any offer button on screen. Is it a bug or i do something wrong?

Usually there is a heart with a plus sign to the right of the players name. If you click that it will put the player in a favourites list, but I don't see that either. Try to reload?

Yeap! Many times, not only once

The negotiation list consists of players from more than one level / server, which means that not all the players will be available to you for making offers. In all honesty, most of the players on negotiation aren't there by their managers' desire, and you will find it hard going getting any of them, unless you make a substantial offer. You are better off most times going with the TL or Mr. Scout.

Does the manager have the option of refusing all negotiations?

You can only refuse individual offers as they come in..
The easiest way to not get them at all is make sure your players aren't about to go up to the next star, that is when they get put on the list.

Thank you, Cat