when clicking add product or edit product, turn up errro 500

-- HikaShop version -- : 3.1.1
-- Joomla version -- : 3.6.2
-- PHP version -- : 7.2.3
-- Error-message(debug-mod must be tuned on) -- : Fatal error: Declaration of JToolbarButtonHikapopup::fetchButton($type = 'Modal', $name = '', $text = '', $url = '', $width = 640, $height = 480, $top = 0, $left = 0, $onClose = '', $title = '') must be compatible with JToolbarButtonPopup::fetchButton($type = 'Modal', $name = '', $text = '', $url = '', $width = 640, $height = 480, $top = 0, $left = 0, $onClose = '', $title = '', $footer = NULL) in /home/aonepart/public_html/administrator/components/com_hikashop/buttons/hikapopup.php on line 45

hello

I backup my site on server A and restore it on server B.

in server A the add product and edit product function are fine but in server B when clicking add product or edit product then the page turn up error 500...and the error message shows on the page as above.

I do not know what causes this situation...

please help me to solve it.

thank you very much.

Hi,

That's because the API of Joomla changed with recent versions. So we had to adapt HikaShop too.
So you'll have to update your HikaShop and it will fix the problem.