: Go to Settings > Security and toggle on Unknown Sources to allow APK installation.
: 3DS emulation requires a 64-bit processor (ARMv8 or x86-64) and a 64-bit operating system. Most devices running Android 4.4.2 are 32-bit (ARMv7), making them fundamentally incompatible with these emulators. 3ds emulator for android 4.4.2
: Android 4.4 devices usually have 32-bit processors and limited RAM. 3DS emulation is resource-intensive and generally requires a 64-bit ARMv8 processor and OpenGL ES 3.2 support. : Go to Settings > Security and toggle