Hi,
The blank screen you had during the update process comes from restrictions of your hosting put in place by your hosting company. It's because the install package of HikaShop is quite big. If you ask them to raise the limits in your php.ini, you wouldn't have that problem and there is nothing we can do to avoid that.
I can't say what was the cause of the cart/coupon system not working properly, but caching systems are usually the culprits in these cases since they prevent Joomla/HikaShop to reprocess the page/cart display and thus you don't see the change even though it was taken into account.
Again, that's not something we can avoid. We actually already have systems in place in HikaShop to try to cope with the Joomla cache system so that you can still activate it and use HikaShop normally, but there is nothing possible if it's a third party system caching the pages like Cloudflare.
So I'm sorry you're frustrated but it doesn't look like your issues actually come from HikaShop and HikaShop or its install being broken were just consequences of other things installed/setup in a certain way on your website/server.
We'll be happy to look at issues if you have any further down the road. In such cases, make sure you provide the links and precise steps to reproduce the issue so that we can analyze the situation.
HIKASHOP ESSENTIAL 60€The basic version. With the main features for a little shop.
HIKAMARKETAdd-on Create a multivendor platform. Enable many vendors on your website.
HIKASERIALAdd-on Sale e-tickets, vouchers, gift certificates, serial numbers and more!
MARKETPLACEPlugins, modules and other kinds of integrations for HikaShop
