Fixer erreur joomla 3.5.0 après migration

Suite à migration J3.4.8 vers J3.5, l'erreur suivante apparait en backend et frontend :

Error displaying the error page: Illegal mix of collations (utf8_unicode_ci,IMPLICIT) and (utf8_general_ci,IMPLICIT) for operation '=' SQL=SELECT template, s.params FROM #__template_styles as s LEFT JOIN #__extensions as e ON e.type='template' AND e.element=s.template AND e.client_id=s.client_id WHERE s.client_id = 1 AND home = '1' ORDER BY home: Illegal mix of collations (utf8_unicode_ci,IMPLICIT) and (utf8_general_ci,IMPLICIT) for operation '=' SQL=SELECT template, s.params FROM #__template_styles as s LEFT JOIN #__extensions as e ON e.type='template' AND e.element=s.template AND e.client_id=s.client_id WHERE s.client_id = 1 AND home = '1' ORDER BY home

Merci de nous communiquer un devis avec le temps nécessaire pour fixer cette erreur.