phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '7b2491caf21a4fd9683a92477e3c8461' for key 'PRIMARY'

INSERT INTO phpbb_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in, session_admin) VALUES ('7b2491caf21a4fd9683a92477e3c8461', -1, 1414752211, 1414752211, '365252c9', -1, 0, 0)

Line : 187
File : sessions.php