Steps to reproduce the issue

I search an article by tiping a word and i click on "search" button.

Expected result

Usually i see the list of the news containing that word as result of research

Actual result

I get error 1253. Here the message:
COLLATION 'utf8_bin' is not valid for CHARACTER SET 'utf8mb4' SQL=SELECT a.title AS title, a.metadesc, a.metakey, a.catid, a.id, a.state, a.created AS created, a.images AS picture, c.title AS category, u.name AS author,CONCAT(a.introtext,a.fulltext) AS text, CASE WHEN CHAR_LENGTH(a.alias) != 0 THEN CONCAT_WS(':', a.id, a.alias) ELSE a.id END as slug, CASE WHEN CHAR_LENGTH(c.alias) != 0 THEN CONCAT_WS(':', c.id, c.alias) ELSE c.id END as catslug, CASE WHEN a.state = 2 THEN CONCAT_WS(' | ', 'Archiviato', c.title) ELSE CONCAT_WS(' | ', 'Articoli', c.title) END as section, "2" AS browsernav FROM #__content AS a INNER JOIN #__categories AS c ON c.id = a.catid AND c.access IN (1,1,3,5,10,11,15,16,17,25,26,27,28,30) LEFT JOIN #__users AS u ON u.id = a.created_by WHERE ((a.title LIKE '%paghe%' COLLATE utf8_bin OR a.introtext LIKE '%paghe%' COLLATE utf8_bin OR a.fulltext LIKE '%paghe%' COLLATE utf8_bin OR a.metakey LIKE '%paghe%' COLLATE utf8_bin OR a.metadesc LIKE '%paghe%' COLLATE utf8_bin)) AND c.published = 1 AND a.access IN (1,1,3,5,10,11,15,16,17,25,26,27,28,30) AND (a.state = 1 OR a.state = 2) AND a.catid NOT IN (2,9,19,23) AND (a.publish_up = '0000-00-00 00:00:00' OR a.publish_up <= '2016-04-04 10:23:23') AND (a.publish_down = '0000-00-00 00:00:00' OR a.publish_down >= '2016-04-04 10:23:23') GROUP BY a.id, a.title, a.metadesc, a.metakey, a.created, a.introtext, a.fulltext, c.title, a.alias, c.alias, c.id, u.name ORDER BY a.created DESC

System information (as much as possible)

Joomla 3.5.0
DB 5.5.46 version
PHP version 5.6.15
Web server APACHE

Additional comments