Character Problem

Hi maxguncel. This issue is related to the database character encoding. It’s a replacement character that’s used when the page can’t interpret the character code. If you do a Google search on “wordpress black diamond with question mark encoding” you’ll see many posts and several different recommendations.
Here is a relatively recent one:
https://wordpress.org/support/topic/punctuation-shows-up-as-question-marks-after-upgrade-to-40?replies=5

Hope that helps.