Many "offline fixed" versions require you to disable Wi-Fi and Mobile Data before launching. After moving the OBB:
Bypasses the initial license check, allowing you to play the full campaign in airplane mode. modern combat 4 apk obb offline fixed portable
The file size should be exactly 1,872,456,789 bytes for the main OBB. If it is smaller than 1.8GB, it is a fake or a lite version missing cutscenes. Many "offline fixed" versions require you to disable