When performing an Import to Sharepoint action, Hidden folders and System folders are not displayed in the file explorer.
While importing these types of folders is not recommended, the Hidden and System attributes can be disabled on the folders manually. The following Windows commands can also be used:
attrib -s FolderName /S (removes the System attribute)
attrib -h FolderName /S (removes the Hidden attribute)
The /S parameter is optional. If present, the command will be executed recursively for all folder contents.