When a user enters a unicode character (which can be done using the emoji panel in Win 10) into an attachments comment field, a SQL error is caused.

Entering the unicode character in the text of the post works fine.

SQL ERROR [ mysqli]

Incorrect string value: '\xF0\x9F\x91\x8C\xF0\x9F...' for column 'attach_comment' at row 1 [1366]

SQL

UPDATE phpbb_attachments SET post_msg_id = 1390, topic_id = 115, is_orphan = 0, poster_id = 2, attach_comment = '*** ***' WHERE attach_id = 84 AND is_orphan = 1 AND poster_id = 2

 *** ***  - Issue won't post with characters from error message.  Substituted *** ***