Search box errors

Good morning,
search box functionality stopped working and don't know why.

Ajax search results no more working.
If I add a search key and press enter I receive this error (blanck page)
Fatal error: Class 'JSearchHelper' not found in /var/www/vhosts/mascagniufficio.it/httpdocs/components/com_search/views/search/view.html.php on line 110

I've recently updated Joomla to 3.4.5
www.mascagniufficio.it/en/

Please help me out with this.
Thank you

Hi there, please update to the newest Warp Framework
www.joomlaplates.com/support/documentati...e-the-warp-framework

just updated it,
without "compile less" nothing changged.
But after "compiling less" the website broke.
www.mascagniufficio.it/it/

Please help.
Thank you

layout is completely broke and this is an erro in the page
Warning: DOMDocument::loadHTML(): Unexpected end tag : li in Entity, line: 2 in /var/www/vhosts/mascagniufficio.it/httpdocs/templates/jp-work/warp/src/Warp/Helper/DomHelper.php on line 47

Hi there, I think you did a mistake.
Our Work demo is running the lastest Joomla 3.4.5 with Warp 7.3.12
demo.joomlaplates.com/jp_work/component/...hrase=all&Itemid=101

Please provide us FTP and Joomla access to your website.
Use our secure form to send us the data.
www.joomlaplates.com/contact-us

Just sent you detail for a SuperUser account.
Thank you.