Roof not going down.

[Bibbey1952]

The roof and boot have always worked perfectly until I stopped the other day, put the roof up and 20 minutes later tried to lower it and boot goes up but roof won't go down and there's a loud ticking /knocking noise from the boot area, from the motor, I think, but not certain. Any ideas? 

[Vauxhall Owners Club]

Maybe best to reset the roof mechanism...should say how to do that in your handbook.

Could be some part of the mechanism not playing ball but a reset may sort this