I have downloaded a theme from Elements envato. The customer is very happy, but has now discovered a problem, under the product page.
There are three choices.
The top two do not respond to an item being sold out. So thought about using “visibility: hidden;” on the two.
But the 3 dropdown, shows double of the variants??? Please help!
I would make a guess that you have a JavaScript error in your code. That third dropdown you see will be the default one that is usually hidden. The JavaScript error is likely stopping the code that hides it from running so you see them all.
Without seeing the site live, or console errors it’s not something we could guide you on. If you’re willing to share a url we might be able to narrow down the issue (to either theme code or an app).
Have you spoken to the app developer? Even themes from Envato should have a level of support.
No, i can’t find the support 
Can you help me? 
Can you please provide your store URL ?
Ok , I have checked this and there is an error in option_selection.js , so please provide store access. So that I can fix the issue.
Can you help in another way? The website is my client site.
Can you help me?
