double glazed french doors door will not open catching top bolt?

You dont say if these are PVCu doors, if they are, they are not alligned properly. PVCu doors can be adjusted on the hinges (outside)using an allen key, you may need to remove a plastic cap to get to these adjusters.If its catching at the top, it sounds like you may need to adjust the bottom hinge so that it pulls the door in tighter to the frame thus making room at the top to free the top bolt. There will be other adjusters for say moving the door in and out too, so you could try moving these also. But be careful not to move the problem somewhere else.
If its timber french doors, you may need to force it out without damaging the frame and trim the bolt with a hacksaw, or refit the whole bolt lower would be ideal. Hope this helps.

Jex3
January 2009