The official changelog for 1.6.640 (PC) and 1.6.629 (console) included:
Notice what’s not in the patch notes: “We recompiled the game’s executable with a new version of Visual Studio and changed the Address Library structure.” That’s exactly what happened.
Non-English players could finally purchase the Nix-Hound pet and Horse Armor again, as localization errors had previously blocked these transactions. 2. The Impact on Modding: "The AE Update"