phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '4f51db55af12abe6502e569db5d4f8e5' 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 ('4f51db55af12abe6502e569db5d4f8e5', -1, 1770354559, 1770354559, 'd849d868', -9, 0, 0)

Line : 187
File : sessions.php