So you mean I can’t use the klein theme? And why should I add that code to Twenty Thirteen, Twenty Fourteen, Twenty Fifteen? Is it so you can test?

Hello Alexander,

There is no problem using the klein theme. But conflict is creating only this particular task. I have test several way to made this code work for you. But When I had pasted this code in Twenty fifteen this is working as usual and I see gallery image is below the product. Did you check this? If not please check yourself and see the result.

Thank you.

I tested and it works just fine with the Twenty fifteen theme but not the klein theme.
But you can’t see why it’s conflicting? Should I contact the author? If so, what should I ask for?

Hello Alexander,

We did not find any exact reason yet. So I can not tell you where the problem lies. We always do any development work with compatible for the WordPress default theme.

What I can say is there could be a .js compatibility issue. You can contact with theme author to investigate if they are still using any backdated script.

Thanks.