When I try to install a theme purchased from themeforest, I keep getting this error message.
zip does not contain a valid theme: missing template "layout/theme.liquid"
This is my source file unpacked.
Couple of things:
1. If this is from theme forest, are you sure its a theme meant for Shopify? Shopify themes have a very strict folder structure. You can see a list of available templates here https://shopify.dev/docs/themes/theme-templates. The screenshot you uploaded doesn't seem to have any shopify theme files. If this theme is meant for shopify, there might be a build step that combines all those files and spits out a proper Shopify theme format (can't tell from that screenshot alone).
2. This sub forum is meant for the New Online Store Design Experience beta. If you're not part of the beta, you might have better luck getting help in https://community.shopify.com/c/Shopify-Design/bd-p/ecommerce-design