We've got a double glazed back door with that multi point locking system and
for some
strange reason the door's got stuck and won't lock/unlock or open. Having
said that I can
open it by using the key but it won't multi lock. With the key in and turned
it just seems
to work the latch at the moment.

After opening it I can see that the handle isn't working the latch or
operating the multi lock system.

is this a fairly simple fix?

Any ideas?

Cheers.