Modern Combat 4 is considered . Gameloft no longer sells it on the Play Store, offers no customer support for it, and the multiplayer servers are permanently offline. Downloading a "fixed" APK for a game you cannot legally purchase anymore exists in a legal grey area for archivists.
Modern Combat 4 was designed for older Android operating systems and hardware architectures. If you try to download a standard, untouched APK today, you will likely run into several brick walls:
: Disables the mandatory internet check that usually causes "Invalid License" errors. Compatibility