Hi there,
I’m using the latest Android version 16.2 on my Zirconia. It runs significantly better than the previous version 15. However, for the past few days, I’ve had two pending updates for “Google Messages” and “Contacts” that won’t install.
I’ve already tried manually installing the updates several times, restarting the phone, and clearing the Play Store and app cache – unfortunately, without success. I even uninstalled all updates for these apps, since the apps themselves can’t be uninstalled. That wasn’t a good idea, because the older updates can’t be restored. The Play Store only ever tries to install the latest update. 
Under Play Store > Profile > Settings > About, I see that the Play Store version is 50.7.24-31 and there’s no update available. The “Play Protect certification” shown there is also missing and can’t be repaired. As a last resort, I would reset my phone, but I definitely don’t want to do that.
Am I the only one experiencing these update problems, or is this a known issue?
best regards
Nico