The most reliable, legal, and user-friendly source for these specific ROM sets is . This guide will walk you through everything: from understanding the "set," to downloading from Archive, to perfect installation on your Android device.
You are missing neogeo.zip . Download the 0.139u1 version of neogeo.zip from Archive.org and put it in your ROM folder alongside your game ZIPs. Do not put it inside the game ZIP.
This is a very common setup for Android devices, as version 0.139u1 corresponds to the "MAME 2010" core, which is one of the most stable and widely supported ROM sets for mobile devices.
: Open the app. It will ask for permission to create a directory for your games. By default, this is often /storage/emulated/0/MAME4droid/roms/ . 3. Move the ROM Files