Do not just download the APK. Version 6b requires a separate .
However, simply downloading the Mini Militia 6b APK from Uptodown often leads to installation failures on modern phones (Android 11+). This is where the becomes necessary. Mini Militia 6b Download Uptodown Fix
If you downloaded 6b from Uptodown but still get a signature error, someone may have modded the APK (infinite ammo, jetpack, etc.). Many "6b" files online are repackaged malware. Do not just download the APK