Can't open product pages anymore

-- HikaShop version -- : 2.5.0
-- Joomla version -- : 3.4.3

Hi my shop had been working perfectly but now for some reason I cannot open any of the products - they redirect back to the index page instead.
I have cleared caches and tried disabling 3rd party plugins but nothing works.
Its the same issue in all browsers.
Please see this link - click on "Vouchers" then try opening any of them and you will see they return to the index page
ballincolligdental.ontargetdev.eu/index....ift-vouchers-ireland

Ok the issue is the canonical URL in the product