The "Checking Expansion File" message appears when the game tries to verify that the necessary data files (usually found in Android/obb/com.rovio.gold ) are present, uncorrupted, and valid. If the app cannot find this file, or if the file is not correctly linked to the installed version of the game, it gets stuck in an infinite loop checking for it. Why Is This Happening to You?
Then, the message appeared. The enemy. The arch-nemesis that made King Pig look like a harmless ham sandwich. angry birds epic checking expansion file