phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry 'a518a71594d4a0e70b22284b1d7fdd3c' 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 ('a518a71594d4a0e70b22284b1d7fdd3c', -1, 1767984601, 1767984601, 'd849d887', 4, 0, 0)

Line : 187
File : sessions.php