Need help escaping with cleric
 

On the first MSF mission where you get to choose between giving Cleric to Viper or not, I have a small problem with my mothership constantly blowing up for no reason and not being able to get through the portal even though cleric says its now open. Ive tried the two new jerusalem portals and this happens on both. I can get through the portan on the left but that doesnt continuee the mission adn I randomly blow up if i go towards Ashelon. Any advice or is this mission broken?