the lock has gone stiff to operate ,i have measured the diagonals, and they are 15mm out of square. when i operate the lock with the door open, it works freely. there are no identification marks on the lock strip,but it has two hooks and two rollers
if the hinges on your door has a small rubber bung on the end of it take it out and put an allen key into the hole turn clockwise or anticlockwise this will adjust your door do this with the bottom hinge as well