To understand why you need "all DLCs full," you must understand how the four expansions interact. They do not exist in silos; they stack, twist, and sometimes violently collide.
I notice you're asking about (likely a typo for 1.4.3901, as 143901 doesn't exist) with all DLCs — specifically Royalty , Ideology , and Biotech . rimworld 143901 all dlcs full