phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '5a87346e2c5d0ac91444d87ecfde9b18' 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 ('5a87346e2c5d0ac91444d87ecfde9b18', -1, 1789256707, 1789256707, 'd849d9ad', -4, 0, 0)

Line : 187
File : sessions.php