If you get a scheme that has files referenced that don't exist in your data.zip, you'll get a reboot loop. All you need to do is delete THAT scheme under apl2\igo\content\scheme and it will revert to the last used scheme and boot fine.
It's also safe to just delete everything under user\userdata as any file error in there will cause a reboot loop. This will nuke all saved favorites, home address, history, phonebook, EQ curves, etc. The avic will be like the day you first installed it.
it will revert back to pioneer colorschemes and wallpaper, but any custom schemes and skins will still be installed including the data.zip.