phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry 'dcf87570f08bb0974d1530d59c96e3bc' 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 ('dcf87570f08bb0974d1530d59c96e3bc', -1, 1770038878, 1770038878, 'd849d817', -4, 0, 0)

Line : 187
File : sessions.php