Facebook App Will Not Update

Got this myself on my phone, as well as it just refused to update. Here's what helped me.

Edit: this appears to be an issue that Facebook recognize. It's a concern with the Facebook app, as well as not a generalised Play Store issue.

This is what worked for me at the very least.

Settings > Apps > All > Google Play Store, Clear information and Clear cache

Settings > Apps > All > Google Play Provider > Manage room, Clear all information and also Clear cache

It doesn't hurt if you reactivate your phone prior to you try upgrading facebook again. As well as, the install was SLOW. Just at the very least 4-5 mins. However, it did work. If not try to uninstall it, or just wait on a fix.