Whenever I try to sign into the Apple Store, nothing happens

Whenever I Try to sign into any Apple account, it loads for a bit, and then stops and does nothing. Sometimes it comes up with a pop up saying it can't sign in. I've reset my iPad with IOS 8.3 many times and checked my date and time settings, also I reset my network settings, yet nothing worked. I've signed into the same account on different devices and it works fine.