Cannot connect to iTunes account

Hey guys,

if I want to connect to my account on iTunes store, the log in screen repeats instantly over and over again.

So if i log in, the screen just come again - and again, and again...

I tried with a wrong password, then it says "wrong password". So it must work, I think, but I dont see my account information.

If I try to login in my iPhone or on the Mac OS store, it works fine. So I only got this problem with iTunes on my MacBook Pro 13" retina late 2013 (256gb/8gb).

Hope you can help me!