I Updated Facebook and now It Won't Work
Edit: this seems to be a problem that Facebook are aware of. It's a problem with the Facebook application, as well as not a generalised Play Store problem.
This is what worked for me a minimum of.
- Settings > Applications > All > Google Play Shop, Clear information as well as Clear cache
- Settings > Applications > All > Google Play Solutions > Manage space, Clear all data and Clear cache
It doesn't harmed if you restart your phone before you attempt upgrading facebook once more. And also, the install was SLOW. Simply at least 4-5 minutes. However, it did job. Otherwise attempt to uninstall it, or merely wait for a repair.