phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '5171881c2ca20d49540b52b48be12a05' 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 ('5171881c2ca20d49540b52b48be12a05', -1, 1770780918, 1770780918, 'd849d821', -9, 0, 0)

Line : 187
File : sessions.php