The shifter in my 2013 Range Rover won't turn

This is actually more common than you might think in cars with this type of rotary knob gear selector.

There are a couple of major causes. The first is a blown brake light or brake light switch, believe it or not. Many modern cars are set up so that unless the driver has their foot on the brake, the car won’t move out of Park. If the brake light switch (or sometimes even the brake light globe) fails, the car doesn’t get the message that the brakes are applied and the car won’t shift out of Park.

The other possibility – and it’s not unknown on Range Rovers – is a flaw in the circuit that turns the knob’s twisting action into an actual gear selection at the transmission. A specialist might be able to take the circuit apart and replace the blown component, restoring operation to normal.