please have a look at the documentation here, as you can see in prerequisites, the user running the DSS process needs write access to the DSS install dir. The dssadmin command is not supposed to be run as root, however if it finds that you miss some dependencies, it will suggest you a command that you will need to run as root.
My suspect is that your install-dir is not owned by the same user running DSS, or at least part of it. You can test it listing the folder itself and its content. It is recommended this folder is owned by the same user to avoid incurring in errors using DSS. This folder is frequently used by DSS because it stores libraries, executables and other helpers used by DSS for its functions.
Please let us know how it goes and in case this solves your issue please flag this answer as accepted.