phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '4f28a18c0e96b383ec2123ac3467b56f' 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 ('4f28a18c0e96b383ec2123ac3467b56f', -1, 1768504556, 1768504556, 'd849d86d', -4, 0, 0)

Line : 187
File : sessions.php