sku totally missing from back and frontend

It’s on the ‘general’ tab when editing a product. Plugins can turn it off with a filter though, so ensure you’ve not customised it to be hidden.

I know where it is, because in other sites i’m managing i’m using it!
I made no customizations yet, so I don’t know what’s happening.
Any other solution?

You need to find the code/plugin/theme disabling it. https://github.com/woothemes/woocommerce/blob/fcb4dc79cb6d0b08d976d120cb87d8b3b69ffc7d/includes/wc-product-functions.php#L62

Ok, i’ve found these lines

add_filter( ‘wc_product_sku_enabled’, ‘__return_false’ );
This is in the theme functions.php

function wc_product_sku_enabled() {
return apply_filters( ‘wc_product_sku_enabled’, true );
}
This is in the wp-product-functions.php of woocommere.
I set this last one as false, but nothing changes.

I’m not a coder, so perhaps the problem is in my theme function.

Remove:

add_filter( 'wc_product_sku_enabled', '__return_false' );

It has been turned off deliberately.

Ok thank you very much!