I'm on 930 and have only MS account and facebook linked to it.
Actually I mainly use cortana reminders so I really do not need to open the calendar app, and tile and reminders are working.
I was just curious to know if someone unistalled and reinstalled, too lazy to do it myself today, maybe I'll try that sooner or later!
Uh so it's not low ram problem & too many account issue, I think. I've tried to unlink facebook but still no luck.
My live tile & reminder is still working after re-link facebook calendar the birthday & events reminder is still work, but can't be opened (this is not like WP8.1 when events from FB goes to FB app if I tap it, in W10 it just open the Outlook Calendar).
Btw you can't uninstall outlook app, maybe someone would do hard reset, because I'm too lazy to do it too, haha
I hope Microsoft staff see this thread or read our feedback.