You might encounter an error message when trying to enable inactive drives from macOS High Sierra:
If you encounter that error message, please check the file system you are currently using:
If you are currently using APFS:
Upgrade your Hornetdrive Client to version 4.5.3 or later and try again. To upgrade your client, download the latest client version from our download website and follow the installation instructions.
Information about products not created by Hornetsecurity, or independent websites not controlled or tested by Hornetsecurity, is provided without recommendation or endorsement. Hornetsecurity assumes no responsibility with regard to the selection, performance, or use of third-party websites or products. Hornetsecurity makes no representations regarding third-party website accuracy or reliability. Risks are inherent in the use of the Internet. Contact the vendor for additional information. Other company and product names may be trademarks of their respective owners.