You'll need to send us a Support ticket so we can work with you to get your game running :)

http://www.gog.com/support/contact/technical_issues_with_games/massive_assault Massive Assault support link.

http://www.gog.com/support/contact/technical_issues_with_games/massive_assault_phantom_renaissance Massive Assault: Phantom Resistance support link.

Please use the link that corresponds to the Massive Assault game you are experiencing problems with :)

It depends on what the issue is and how long it takes to investigate it :)