Formatting buttons for text in Product Description do not work

-- HikaShop version -- : 2.6.4
-- Joomla version -- : 3.6.4
-- PHP version -- : 5.5.24
-- Browser(s) name and version -- : Firefox and Chrome
-- Error-message(debug-mod must be tuned on) -- : None
Just doesn't work

Hi There
Under "Products" when I try to edit the text under the "Description" section, none of the formatting buttons are working.
Which means I cannot change the font size, font colour, or underline or bold.
When I click on the font colour "A" icon it does not even give a drop down menu with the colour options. Similar for the font size - no drop down menu appears.
However the picture button for adding pictures still seems to be working fine and I can swap between preview and code and editor.