I cant open the convertible roof.

you need to see a mbz tech cannot help without seeing the car. sorry

Is switch Blinking fast or slow make sure luggage cover ( not sure if that's the name ) in trunk is pulled closed. You can release pressure of hydraulic by turning screw in trunk with flat head screw driver then turn back to right to reset it's u can check fluid level in hydraulic tank 10mm wrench a bunch of bolts remove plate in trunk against rear seat. I had to change hydraulic cylinder underneath trunk lid o ring was bad wasnt maintaining enough pressure