phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '977212474cd6ae8fbac9b3b5cab3761d' 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 ('977212474cd6ae8fbac9b3b5cab3761d', -1, 1788910370, 1788910370, 'd849d94f', -4, 0, 0)

Line : 187
File : sessions.php