I have trouble with Apple ID login

I recently had trouble with my Apple ID, Then Password changed. The change has gone through successfully my iPhone. But every time I enter it into the box on my computer, it says "The action could not be completed at this time." If i enter the new password, it says "Password is incorrect." or something like that. Why are these messages different? I get the same thing when I try to do it in the App Store and iCloud. But it won't even let me sign out of iCloud without the password. What do I do?