Hi there,
I checked your website and it seems all the Javascript files of the Envira Gallery loads ok, but the actual images of the gallery are not loaded. I see this error message:

I am not sure why your server throws net::ERR_INSECURE_RESPONSE error, maybe there is a firewall or security measure preventing the file to load correctly.
I tried to separately open up one of the failed images and here is the result:

It seems that the Envira gallery tries to load the images with HTTPS protocol but the website itself is not HTTPS enabled and that is why it throws that privacy error.
I think you will need to contact your hosting service provider to get a better help regarding this issue.
Thank you.