Warning: Illegal string offset 'class'

-- url of the page with the problem --
-- HikaShop version -- : 2.2.2
-- Joomla version -- : 3.2.0
-- PHP version -- : 5.4
-- Browser(s) name and version -- : Firefox 25
-- Error-message(debug-mod must be tuned on) -- : Error_message

I'm getting this message, what should i do?

Warning: Illegal string offset 'class' in /.../public_html/libraries/cms/html/html.php on line 965

Warning: Illegal string offset 'class' in /.../public_html/libraries/cms/html/html.php on line 966

Warning: Illegal string offset 'class' in /.../public_html/libraries/cms/html/html.php on line 966

Hi,
This error don't seems to be caused by Hikashop, you should directly check the code of the lines 965/966 of your file : "/.../public_html/libraries/cms/html/html.php"

i've just updated joomla and istalled hikashop. I haven't changed anything.

965: $attribs = isset($attribs) ? $attribs : 'input-medium';
966: $attribs = trim($attribs . ' hasTooltip');

but maybe hikashop is doing something that joomla don't like
1. forum.joomla.org/viewtopic.php?t=826224&p=3106205
2. or its php 5.4 related: phpexcel.codeplex.com/workitem/17923