I have tested in app purchase for a long time.
For testing in app purchase I have use TEST USER that I have crated in iTunes Conect.
But now when I try to sign in with my TEST USER account I get this message (before this message not appear)

So, this means that I have to enter all info about myself (bank account and etc). But I think for test user this items not needed.
Thanks for help!
This often happens if you accidentally attempt to purchase real content with a test user. Try defining a new test user and deleting the old one.