This error occurs if the OBB file is missing, corrupted, or placed in the wrong directory. Double-check that the com.glu.flc2 folder is located inside Android/obb/ on your internal storage, not your external SD card.
Crucial: Do open the game yet. If you open it now, it will display a file verification error. Step 4: Extract and Place the OBB Data frontline commando d day apk obb download