I found this posting on the Google Nik site. It refers to an unresolved problem with the Google version of Viveza that may have carried over to the DxO version. See the link for details.
The user reports the problem is when Ariel font is deactivated, Viveza fails. See the last post in this thread: https://productforums.google.com/forum/#!topic/nik-collection/Y_h4JWkD00o