Wimbledon organizers have apologized and explained that “human error” was the reason behind the electronic line-calling system being turned off during a match on Sunday – and the tournament subsequently has removed the ability for operators to manually halt the tracking of the ball.

Russia’s Anastasia Pavlyuchenkova has questioned the bias of the officials at Wimbledon after controversial calls during the fourth-round contest against Britain’s Sonay Kartal.

Kartal shares her thoughts on the Wimbledon electronic line calling system malfunction and Pavlyuchenkova's complaints.