phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '86f4ceda3331b3b48dd6f4b2a728adcb' 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 ('86f4ceda3331b3b48dd6f4b2a728adcb', -1, 1771821964, 1771821964, '2d971ed8', -9, 0, 0)

Line : 187
File : sessions.php