iMessage and FaceTime problems on iPad

I have been using iMessage and FaceTime for months but my iPad froze and I had to reboot it. Since then, I have had trouble using iMessage and FaceTime. It has lost all of the settings.

When I go to log in to either of them, it asks me to use my apple i.d. and password to activate them. After signing in, it tells me that I "could not log in. Please check your network settings and try again".

This is only a wifi iPad and I am connected to the wifi and all is OK with the connection.

Any ideas and help would be appreciated!