When I unlock or open the door to my 01 RR the interior lights do not come on. This happens at all doors and even when I open the Bonet?? Is there a simple fix to this???

 

Check lighting fuses and interior light relays.
It almost sounds like it isn't seeing the doors open.
Can you turn the dome light on manually to be sure the circuit works?
If it isn't a fuse or obvious relay; take it to the dealer.
This may be a routine failure that a RR mechanic can identify instantly.