PDOException: SQLSTATE[HY000]: General error: 1267 Illegal mix of collations (utf8_general_ci,IMPLICIT) and (utf8_unicode_ci,IMP

Hello.

When I install CTools plugin, taking this Error.

PDOException: SQLSTATE[HY000]: General error: 1267 Illegal mix of collations (utf8_general_ci,IMPLICIT) and (utf8_unicode_ci,IMPLICIT) for operation '=': SELECT s.uid, c.updated FROM {ctools_object_cache} c INNER JOIN {sessions} s ON c.sid = s.sid WHERE s.sid <> :session_id AND c.obj = :obj AND c.name = :name ORDER BY c.updated ASC; Array ( [:session_id] => WoYfJXDYxX6o0jDx7imeq9-vEZiemQ0XgnCAsltXDJI [:obj] => view [:name] => answers_to_a_question ) in ctools_object_cache_test() (line 114 of /l10/sites/all/modules/ctools/includes/object-cache.inc).

I've changed my db and tables charecter sets to uts8_unicode_ci, but still taking same error.

I see admin panel, deleted all caches. What's wrong?