Cannot save feed content form when using CSV parser and directory fetcher

This is not a Feeds problem but a Clientside validation problem.
In Drupal context, I think we should extend the URL validation to accept `public://` and `private://` scheme.

I proposed the fix on Clientside validation module following your suggestions

https://www.drupal.org/project/clientside_validation/issues/3356402 🐛 URL validation to accept `public` and `private` urlscheme Fixed

It looks like that 🐛 URL validation to accept `public` and `private` urlscheme Fixed is resolved, so this is probably no longer an issue here.