A compatible figure means the items and character system that your products will work with. Genesis 8.1 has enhancements which are only available to characters that are 8.1.
The enhanced capabilities of 8.1 are not backward compatible; therefore, you will not be able to apply the new skins and capabilities on a Genesis 8 character. In order to access our new skin shader for Genesis 8.1 character(s), a required update is necessary for Daz Studio.
Refer to the article “How to update Update your Daz Studio Default Resources package (DIM or DazCentral) to 4.15+.”