A special character I am trying to include in a page keeps getting rejected with error “Updating failed. The response is not a valid JSON response.”

A special character I am trying to include in a page keeps getting rejected with error “Updating failed. The response is not a valid JSON response.”

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)