The disclosure relates to a technology for allowing access to an area having a blocked entrance, wherein the blocking of the entrance is controlled by an access controller arranged to unblock the entrance upon receipt of an authorized credential. The technology is implemented to repeatedly updating an override credential in the access controller, sending updated override credential the access controller to a remote node, repeatedly checking the connectivity between the remote node and the access controller, detecting failure of connectivity between the access controller and the remote node, setting the override credential as an authorized credential in the access controller in response to the detection of failure of connectivity, and allowing access through the blocked entrance upon receipt of the override credential in an access request to the area received by the access controller.