phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '08d55850351653cb999d504ba4dbe490' for key 'PRIMARY'

INSERT INTO sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in, session_admin) VALUES ('08d55850351653cb999d504ba4dbe490', -1, 1475063880, 1475063880, '365bf3af', 15, 0, 0)

Line : 187
File : sessions.php