Crash on mobile devices

We are using popup builder to show the pedigree of the horses on the site – but for some reason when we have the popup builder plugin activated on the site it crashes for some mobile devices.

Have you experienced this issue before and how can we prevent this from happening.

For now we have disabled the plugin so it is not crashing the site further.

I can give you an admin account so you can see for yourself.

The page I need help with: [log in to see the link]