phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry 'c31e5a1af5f1917b1d89aef21eacc7f1' for key 'phpbb_sessions.PRIMARY'

INSERT INTO phpbb_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in, session_admin) VALUES ('c31e5a1af5f1917b1d89aef21eacc7f1', -1, 1770249862, 1770249862, 'd849d88f', -4, 0, 0)

Line : 187
File : sessions.php