I also had the infamous "error 495" on my Samsung Galaxy S2 running Android 4.0.4. I searched for 4 or 5 hours online, cleared my app cache, un-updated Google Play (it didn’t work and completely uninstalled it; fortunately, it reinstalled without a problem), stopped the Play service, etc etc etc and rebooted about 12 times. After reading some forums, it seemed that the time of the device and the network could have played a role. Indeed, it might have stopped working after I left the US to Europe and now India.
What was really weird is that some apps would install or update but most would not. The green bar would move and move but without any progress or indication of what was happening.
I also lost some time because my system partition is almost full and I thought it was that. It turns out it's close to impossible to remove anything in it (and is it possible/desirable?)
The only way I found to manage to start updating apps is to make it believe that it was in the US... I set the time to US EST, and connected to a US VPN. It started updating one of my apps, albeit so slowly that the VPN cut before it could finish... I need to try again with a paid VPN… :(
Why would my phone not update when I'm outside the country? Is it Google or AT&T? Is there any setting that I can change? What are the workarounds? Connecting to the VPN every time is not very practical...
By the way, and I don’t know if it’s connected or not, my GPS works very poorly abroad – any suggestion?