Is it safe to update to the current version?

Hi,

We've had people updating their HikaShop without issue from a 2.x to a 4.x but it depends on how the template is made and the more the shop is customized the more problems will happen.
So it's best to expect problems.
I would recommend to first do a copy of the website and try the update on the copy. If all looks fine, then you can do it on the live website and if you see issues, then you can ask us what to do and we can tell you. Usually, it's a bit of tweaking of the CSS or changing one or two options in HikaShop or disabling or our two view overrides.
For our demo website, which has a lot of HikaShop view overrides in the template, we had to spend half an hour to modify the CSS and disable view overrides to have it working when updating from a 2.x to a 3.x. Since then, the updates have been quite smooth on our demo website.