rear sliding door wont open???

[minimadd]

helloo :wave: - wondered if anyone can help?? we bought another berlingo at the weekend but we have a problem I haven't come across before ! - one of the rear sliding doors has now locked and wont open again?? sounds like the central locking is working and the handle feels firm but you cant open the door from either the inside or outside :brickwall: and need some pointers before I take the door apart from the inside - any help would be appreciated - thanks !!