vauxhall movano?

Hi everyone, please help if you can , i have a Movano, i have replaced battery in key fob, now the central locking doesn`t work, i was able to start it earlier but now i can`t and the immobiliser light is flashing, i have tried the option on here to turn key to position 2 and press button on/off but no joy, wouls really appreciate any help, cheers lyn