Database Error!

Error: Field 'last_seen' doesn't have a default value
Query: INSERT INTO users (uid, password, ip_address, first_seen) VALUES ("5d88298cadc198.78395930", "ebQfP3u1JpADbW9LWi5NR6TNS3YzBDjg", "3.227.233.55", UNIX_TIMESTAMP())
File: /includes/database.class.php
Line: 98
Backtrace: