I configured my custom device just as Bucky did in Android App Development for Beginners - 7 - Create a Custom AVD. Now, whenever I launch the emulator it says in the screen "Android is upgrading" and a little bit down there "starting apps" but it never finishes loading the apps. I let the emulator run for a whole night and the next morning the same screen was still loading. This doesn't happen with the default emulator Nexus 5.