How to Solve / Fix "Error Code 495"
921, 923, 927 and other errors - downloading or updating apps can be fixed with the following steps.Go to Settings > More> Application Manager > Google Play services
Click on the Clear Cache button and Clear Data button. If that does not work, repeat the same steps with restarting your phone. Power off and then back on.
That usually works, but sometimes errors pop up during downloads in progress. If that happens, close and restart the Google Play Store app and restart your download. If the error occurs again during your download it's because you're downloading via WiFi, and this is the reason. Not to worry, just repeat the steps above and restart your download, you'll notice it doesn't start over from the start, but picks up where you left off or where the error occurred.
Sometimes that doesn't do the trick, but most of the time it will. When the above does not work, you can try the following...
Activate Access Settings App:
Sometimes the location settings can mess with the Play Store and stop apps from getting downloaded especially in countries other than the US where the app may be restricted.
Settings > More >Location services > Access to my location > Use GPS satellites > Use wireless networks.
Make sure all three boxes are checked.
This should do the trick and get rid of the 495 error.
It has been discovered that uninstalling the Gmail app sometimes fixes the problem. You could always uninstall and then re-install your Gmail app. This workaround is a bit more drastic and one that I would not recommend because it may not eliminate the errors.
As A Last Resort:
As an absolute last resort you could do a Factory data reset. Before doing this make sure to back-up all of your data to an external SD Card.
Then and only then...
Cross yourself, pray to God and beg for forgiveness, clutching a rabbits foot and crossing your finger before throwing a pinch of salt over your shoulder, kneeling with teary eyes staring into the heavens above ...Go to Settings >Accounts > Reset > Factory data reset, and may God have mercy on your soul!