This is a bug in the Google Play Store application. It shouldn't appear anymore these days because these errors have been fixed a long time ago. However, if you have this error, read below how to fix it:
- Go to Android's Settings application.
- Tap on Applications Manager > All.
2.1 Tap on Google Play Store, then "Clear Data and Cache".
2.2 Tap on Google Play Services, then "Clear Data and Cache".
- Reboot the phone
After the phone completed the reboot, attempt to download the applications again and it should work normally this time.