Apple Mail messages/folders not appearing in Windows Live Mail

I have been using Windows Live Mail with Apple Mail installed for years with no problem. In March the Apple Mail folders stopped updating. I have reinstalled Apple Mail and made the Apple folders visible, but there is no content in any of the folders. I can move a message in Windows Live Mail to a Apple folder and message appears in that folder in Apple Mail, but not in the same folder in Windows Live Mail. In the Apple Account property settings in Win Live Mail, under Imap, "check for new messages for all folders" is checked but the Root folder path is blank. I don't know what the Root Folder Path is.