Facebook Update android Problems
Edit: this appears to be a problem that Facebook know. It's a problem with the Facebook app, and not a generalised Play Store issue.
This is what helped me at the very least.
- Settings > Apps > All > Google Play Store, Clear information and Clear cache
- Settings > Apps > All > Google Play Provider > Manage area, Clear all information as well as Clear cache
It does not hurt if you reactivate your phone before you attempt updating facebook once again. And, the install was SLOW. Simply at least 4-5 minutes. However, it did work. If not try to uninstall it, or merely wait on a repair.