"Complete" button in quests is broken

Hello.
I was a little quick clicking the "Complete" button when finishing a quest once... then the button grayed out, like it was clicked, but the quest didn't finish. Now, when I am trying to complete the quest (or any other quest) again, the same problem remains. "Complete" button is grayed out, and I cannot complete any quests anymore, since the problem is omni present in the game for me...
I have tried logging in and out of the game. even restarted it completely, and the problem still remains.. My quest log is also not full, I only have a few quests in it for the moment. It still won't let me complete my quests (I have tried three different quests, for the time being, both have the same problem... in different zones, so it seems that the problem is present through all of ffxiv for me.

This is clearly a bug, and I would like to get it fixed so that I can continue playing this game.

Thanks, and regards.

Do any of the quests have rewards that you need to choose before it will let you complete it?

Ahh... yes, that might been the problem! You are right, I had to choose an item from rewards. *facepalm*