Make sure you have the latest version of the PokerStars app installed and restart it. If you have a firewall or security software, make sure it allows the PokerStars app to access the Internet. Restart your PC / smartphone.
On April 15, 2011, the U.S. Attorney's Office for the Southern District of New York seized and shut down Pokerstars and several of its competitors' sites, alleging that the sites were violating federal bank fraud and money laundering laws.