Error in anticitizen?

[pipmelons]

A bit of a problem... i was happily progressing through anticitizen in half life 2 to the point when gordon meets up again with alyx... kill the combine guys and alyx explains about taking out the generator core with the gravity gun... but then on leaving the control room the exit door is still shut?? so me and my wee squad are trapped in that building... forever? can anyone help, cos it seems like a bug to me...

 

[RandwulfX]

I am having a similair problem, but for me it looks like rubble has fallen down and blocked the path out of the building ;(
Do I have to restart from a previous save point?

 

[AciD]

Could you post a screenshot?