Because later DLCs like Dark Waters (naval counter-terrorism) introduced new mechanics (fast-roping, night-vision rework) that are hardcoded into the executable. A partial unlock grants map and weapon access but cannot activate engine-level features.
Detailed weapon and character customization, including "Supporter Edition" gear if the DLC is unlocked troubleshooting for this specific version? Ready or Not v39903 (Release) + Partial DLC + Multiplayer Ready or Not v39903 -Release- Partial DLC M...
If you want, I can tailor this review for a Steam store page, a short social media blurb, or expand into a more detailed pros/cons table. a short social media blurb