The warning message indicates that predefined roles referenced by the users and roles that you have created in the previous version, no longer exist in the Denodo version 8.0 hence the definition of these roles and users are modified to remove these references. This will not affect the export process.
Note that these modifications are made to make the roles and users compatible with the Denodo Platform 8.0.
Please take a look at the [Upgrading from Denodo 7.0: Export the Settings and Metadata of the Current Installation](https://community.denodo.com/docs/html/browse/8.0/en/platform/upgrade/export_the_metadata_of_the_current_installation ) section of the Denodo Platform Upgrade Guide for more information regarding the warning.
Furthermore, if you still need help and if you are a valid support user then you can raise a new support case in [Denodo Support Site](https://support.denodo.com ) so that our support team can help you.
Hope this helps!