Whenever you are exporting a reference from a database or the library catalog, this message will pop up. Choose which RefWorks version you want your citation to export to. If you are a RefWorks legacy user and would like to switch to the new RefWorks, ask a librarian.
Update: The library will no longer support the RefWorks legacy edition starting January 12th 2018. If you are currently using RefWorks legacy a link at the top of your screen after you've logged in (see below) will direct you to migrate to the newer platform. Once the user has clicked on this link, they will be prompted to create an account and all of the contents (references, folder structure, attachments and custom styles) within their legacy account will be moved over to the new RefWorks automatically.