If the +1 button is unavailable or has stopped working, you'll see this image:
A +1 button error can occur for a variety of reasons, including the following:
Server timeout: Check your Internet connection and try refreshing the page.
Suspended profile: If your profile has been suspended, you won't be able to +1 content.
Apps user: If your administrator hasn't enabled Google+ for your domain, you won't be able to sign up for a Google+ account to use the +1 button.
Blocked cookies: If you've disabled 3rd party cookies in your browser you won't be able to use the +1 button.