I recently downloaded a new version of Google calendar (version 201404014) from the Google Play store. After I downloaded it and opened it, I found the application to be dull and less attractive than the original Google calendar that came with my Samsung S3. I decided to "uninstall" the new version and went back to the original application.
Once I uninstalled, the original version no longer synced with my Google account. I was able to see contact birthdays and holidays, but the phone no longer synced. I spent an entire day trying to load, unload and sync every which way possible. I finally went back to the Playstore, reloaded the new application. Once reloaded, I went to accounts and synced it from the calendar application and the original calendar returned to sync. I now have the new version running in a widget (that I don't use) and the original version running that I do use. Hope this helps.
Once I uninstalled, the original version no longer synced with my Google account. I was able to see contact birthdays and holidays, but the phone no longer synced. I spent an entire day trying to load, unload and sync every which way possible. I finally went back to the Playstore, reloaded the new application. Once reloaded, I went to accounts and synced it from the calendar application and the original calendar returned to sync. I now have the new version running in a widget (that I don't use) and the original version running that I do use. Hope this helps.