We are always very accustomed to SharePoint lists and libraries. We always want our documents as well as items or articles to be organized in proper manner so that we can navigate very easily. That path should have proper naming conventions as well as resides in proper folders. Folders are present in list as well as libraries so if you come across a situation in which the ‘create new folder’ option is greyed out then here are the complete steps by which you can get it back.
--Open the list on which you are working on it
--Settings
--List settings
--Advanced settings
-- Select Yes to “Make “New Folder” command available?”
--Make it Yes and that’s it-You are done
If you have any queries/questions regarding the above mentioned information then please let me know. I would be more than happy to help you as well as resolves your issues J Thank you J