I don't have those files. But i can import individual files and folders without issues. (I'm on windows 10)
Have you tried to import other files?
Perhaps try to place a copy of the Echo Sound Works folder in the samples folder here:
OSX: /Library/Arturia/Samples
WIN: C:\ProgramData\Arturia\Samples (ProgramData is a hidden folder, so you must enable windows to show it, to be able to see it.)
Just in case: Are the files unzipped?
Are the Echo Sound Works wavetables any good? If you post here i can try to import, and check if something is wrong when trying to import.