If you happened to have migrated content from an older database to a new version, you might have come across some odd characters like â€” or â€™. This was most likely due to the change if charsets of your database/tables. The following code snippet can be used to replace odd characters in your database.

UPDATE ohp_posts SET post_content = CONVERT(CAST(CONVERT(post_content USING latin1) AS BINARY) USING utf8)

Resources:
Debugging Chart Mapping Windows-1252 Characters to UTF-8 Bytes to Latin-1 Characters