If the game fails to launch due to a missing file (e.g., 3dx9_43.dll or msvcp140.dll ), reinstall the DirectX End-User Runtimes and Visual C++ packages.
An all-inclusive Arma 3 installation features a massive sandbox containing years of official content updates: 1. Core Expansions
While the "Extra Quality" feature gives you all the files needed for servers, a repack is a legal copy of the game.