Google Drive integration is only available on devices running Android 4.4 or higher as Google dropped support for older versions through their library. Is your device running an Android OS version below 4.4? With the next update, I'm going to provide an error message when users on older devices try to access Google Drive so that the crash won't happen. You can still use Dropbox on older versions, so if you need to use the library sync functionality, I would either recommend you sync to Dropbox or you just use the direct device sync option over WiFi, as that's faster than using the cloud anyways. You can just copy the sync folder from Google Drive to Dropbox and the sync should work the exact same way.
Mike
Mike