solution:
1. Goto -> Settings -> click apps ->then select ?All?
2. Next in the all apps view find the ?Google Play Store? and click on it
3. Now click ?Clear Cache? (Not Data), then Force Stop.
4. Next in the same app list find ?Google Service Framework?
5. Click clear data (Not Cache), then Force Stop
6. Switch off the phone or tablet and turn it back on
7. You should be able to download and update apps from the Google Play store once more.
then check by downloading