Google Play Store is not working I updated my Galaxy S3 three months ago and since then, my Play Store went wrong. I can't open it anymore, not to mention my phone often got stuck for hours. I tried every method I could find like resetting the phone, cancel Google account but it just wouldn't work. I can still open apps that I downloaded before, but I can't update them. What should I do to make it back to normal again?
Try going to Settings > Applications Manager > All > Google Play Store and then click Uninstall updates.

It could be that the Play Store data has been corrupted. This will downgrade Play Store and might make it possible for you to launch Play Store which will then update itself in the background, but hopefully correctly this time.