I wouldn’t suggest that you “go back” to
http, as the security warnings are probably going to keep visitors away. Down the road, I wouldn’t be surprised to see the warnings becoming more aggressive or even blocking access altogether.
The easiest and most long-term solution would be is to pick a modern supported theme. The version of qube that you are using is loading jQuery 1.7 (November 2011). The current stable jQuery version is 3.6 (March 2021).
if you are comfortable with coding then you could modify the existing template inside the theme package to simply change the
HTTP links to their equivalents in
I’d have a look over at Themeflood (@willwood). Qube is now sold and supported by Will.
There are also a ton of other themes there, free or reasonably priced and all offer a free trial version so you can see what it looks like with your content.