May be the main reason of this issue is that the WordPress finds that this URLs already assign to any post which exists in database. so You have to check permalinks of the every pages/post or attachments are not using that permalink. It could be in publish, drafts or trash as well.
or you can find in wp_posts table in database from phpmyadmin. you can search using :
wp_posts > search tab > "post_name" operator LIKE%..% value "what-are-impact-goals"
or you can fire SQL query in SQL tab:
SELECT * FROM `wp_posts` WHERE `post_name` LIKE '%what-are-impact-goals%'
Check there is permalink already exists or not. then after you can take action.