cannot post to forum or can I... test

I am trying to post something and I get the error

General Error
SQL ERROR [ mysql4 ]

Incorrect string value: '\xF0\x9F\x98\x8A \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.

I am trying again now, just posting the error message. Maybe my text has some offensive characters...