phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry 'adc88ea6412f9bcacae1ed21d87f4df7' 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 ('adc88ea6412f9bcacae1ed21d87f4df7', -1, 1776019177, 1776019177, 'd849d8a3', 15, 0, 0)

Line : 187
File : sessions.php