My 2014 2.0tdci auto won’t start. Showing warning light Immobiliser malfunction service required. Any help as to what this is about. Should say it is keyless ignition. 

Probably a stupid question, but have you tried the spare key, or changed the battery in the one you are trying to use?

I have spoken to a mechanic who told me sometimes the car does not recognise key. If this happens hold the key against the plate on the steering column, where the key would be and it normally works. It did for me, such a simple fix but a bugger if you don’t know.