phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '2c1bb305c7ca6bd38b7915d153d87d66' 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 ('2c1bb305c7ca6bd38b7915d153d87d66', -1, 1770101256, 1770101256, 'd849d821', -2, 0, 0)

Line : 187
File : sessions.php