phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '987a5c87b3c1e68d915a876d1e050176' for key 'PRIMARY'

INSERT INTO phpbb_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in, session_admin) VALUES ('987a5c87b3c1e68d915a876d1e050176', -1, 1788304763, 1788304763, 'd849d825', -4, 0, 0)

Line : 187
File : sessions.php