Internet accounts can't be loaded

[macwinpraxis]

Since last update of Yosemite (10.10.3) I can not open "internet accounts". It delivers an error massage telling System could not load internet accounts. I created a new user and checked it again, the same error. Mail-app and others work properly with an exception that I can not delete an email account or create a new one. And that's what I need actually.
Please check the function internet accounts (under 10.10.3) and tell me if you have the same problem.
Or do you know any solution?
I am going to install the update of Yosemite again to see if it makes any difference.