automatic door locking error message

Hi all I really need help for a car I purchased from a car dealership. It's a renault Megan scenic, dynamique 2.0. 58 plate.There is now an error message on the dashboard stating check automatic door locking, and the doors in the back won't open from the inside. Please please someone advise as I am now at my wits end. I have tried engaging and disengaging the child lock but it's not working :-(