This is an uncommon error. There is no information available regarding this. However, there are some things that you can do in order to try to fix this. Before you try to download an application, you need to check if your device is properly connected to the Internet and check the available memory. I suggest you clear the cache of the Google Play application. To do that, go to Settings -> Applications -> All tab, search for Google Play, tap on it and select Clear cache. You can also update this application to the latest version available and check for system updates before you try again.