I found in this forum someone who had had the same problem, I wrote a comment there and you did not answer, so here I open it again:

Hello, the CSV Importer functionality in WordPress back end does not work. The following message appears:

This page isn’t working 24f.co.uk redirected you too many times.
Try clearing your cookies.
ERR_TOO_MANY_REDIRECTS

So when I go to ‘Tools’ then ‘import’ then ‘WooCommerce products (CSV) Run Importer’ I receive the above error message.

Ok, so what have i done about it so far:

1) deactivated all plugins and reinstated them one by one
2) cleared cache and cookies
3) premlinks – checked all of this
4) I contacted the hosting provider and they found no problems on their side.