I'm here to help. This can happen sometimes when code is customized, but can be resolved. Let's work on this together and get your store back up and running.
I have a few questions to troubleshoot this with you:
1) What is the name of your theme? We'll be able to determine the level of support for the theme that you have. You can check the name by logging into your Shopify admin, then clicking on "Online Store > Themes". The first theme name that you see will be the current theme. Let me know what that is here, and I'll be able to dig into this for you.
2) What is your store URL? I would love to take a further look and see what you're experiencing to help.
3) What code were you trying to modify? I ask because you may be able to roll back your theme's code to revert any customization made and this would restore your theme's file to the way it was before.
Once I have some more information from you, I'll be able to help!
Tira | Social Care @ Shopify - Was my reply helpful? Click Like to let me know! - Was your question answered? Mark it as an Accepted Solution - To learn more visit the Shopify Help Center or the Shopify Blog