You might like to look at this message on the DxO support site…
General online Support is available only to customers who have purchased the paid version of the Nik Collection by DxO available since June 2018. Comprehensive support and software updates are only available for the newest release of Nik Collection by DxO, and those using the newest trial version.
Previous versions cannot be the subject of a request for assistance, because we have not developed them. However, you will find information on some of the known issues in the FAQs below.
For any stability issues, compatibility with the latest Adobe CC products and the latest Mac/Windows OS, and for future updates and our support, we strongly encourage you to purchase the latest version of the Nik Collection by DxO or to test our free 30 days trial version.
Thank you for your understanding.