If the error is leaving you a message that "the application has stopped Google Play Store" or in English "Unfortunately Google Play Store has stopped working" ... may be because the application that manages the downloads are hung or disabled, and this is solved by going to Settings> application Manager> All, and in that long list to look for and touching the app "Downloads" link in the green Android icon. In there they have to make sure it is not disabled, that is, play the "Enable" button if present, and then "Force Stop" switch off, then on again, and now, and should work fine.