Database Error!

Error: Field 'last_seen' doesn't have a default value
Query: INSERT INTO users (uid, password, ip_address, first_seen) VALUES ("5d59db1af3ab73.29350572", "JC3tLPQbjQLEsRCtenRScks8Ikm9j4WF", "35.173.48.224", UNIX_TIMESTAMP())
File: /includes/database.class.php
Line: 98
Backtrace: