phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '1' for key 'session_user_id'

INSERT INTO sajjad_bbsessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in, session_admin) VALUES ('8048ce30fc1eab6aac08c7cead2518bf', '1', '1513567079', '1513567079', '365270c1', '49', '0', '0')

Line : 207
File : sessions.php