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.

Try these steps: clear browsing data and cookies, disable unnecessary extensions, ensure the download is from the official PokerStars site, and try a different browser. If none of these work, contacting PokerStars support for specific download troubleshooting might be necessary.