"Agent Sirius DLC not recognized" error. Solution: This means you installed the patch over the wrong game version. Update RJ388166 to v1.08 or higher via DLsite’s update section. Then reapply the agent DLC.
This review covers the for the title Deep One , specifically the verified versions found under codes RJ388166 and RJ01259073 . ⚡ Quick Verdict
Appendix: Artifact Mapping
“To threaten a blockade. To make sure the buyer played fair.”