I can't install the Facebook app on Android 6 Marshmallow I have just upgraded my phone (2nd Gen. Moto G) to 6 Marshmallow and now I can't install the Facebook app.

With Android 5 I had the app installed on the SD card (along with a bunch of other apps), but as part of the upgrade it insisted that I format the SD card so it could be used for apps. I'm assuming that the way 6.0 addresses the memory card is different to how 5.x did.

Once formatted I (obviously) lost all the apps that were installed there. I managed to reinstall them all - except Facebook. It doesn't say it's incompatible with my device, it apparently downloads OK but the installation phase just fails silently. I've tried it a number of times (after clearing caches, rebooting the phone, removing Facebook from the list of apps that have ever been installed) and get the same result. It will even crash the Play Store app and/or phone during the process.

I've examined the SD card on the phone and computer and I noticed that there were some folders dated from before today so I'm wondering whether the format was actually a format (or are the dates from the date the OS was created?) and there were still some folders that included "facebook" in their name.

Is there anything I can do to get the app to install - short of reinstalling the whole OS again - or am I just going to have to abandon this one for now?
Go to this link on your phone: Facebook APK
And install the apk yourself but make sure you have unknown sources checked in the developer settings.