When submitting a new extension through the database, I put 👍 in the testing instructions text area and on submit I got the following general error:

General Error
SQL ERROR [ mysqli ]

Incorrect string value: '\xF0\x9F\x91\x8D\x0A\x0A...' for column 'post_text' at row 1 [1366]

An SQL error occurred while fetching this page. Please contact the Board Administrator if this problem persists.

It meant that the queue discussion topic wasn't generated correctly.