I have 2 calendars and a todo list and the birthdays list which i syndchronize with korganizer and google.
The one of the calendars(always the same) and the birthdays are not displayed.
I restarted the server, i reload the calendar, i tried refresh all from akonadi console, without succes.
This happens very often, some times i can see the events and after some reboots they disappear again.
I think that the only way to make them reappeared is to delete the google calendar resource and create it again, until the next time when it will be disapeared again.

These are my installed packages:

[dglent@localhost ~]$ rpm -qa | grep akonadi
akonadiconsole-4.10.5-1.1.mga3
lib64akonadi-devel-1.9.1-2.mga3
lib64akonadi-xml4-4.10.5-1.1.mga3
lib64akonadi_socialutils4-4.10.5-1.1.mga3
lib64akonadi-kabc4-4.10.5-1.1.mga3
lib64akonadi-notes4-4.10.5-1.1.mga3
lib64akonadi-filestore4-4.10.5-1.1.mga3
lib64akonadi-kde4-4.10.5-1.1.mga3
lib64akonadi-next4-4.10.5-1.1.mga3
lib64akonadi-kmime4-4.10.5-1.1.mga3
lib64akonadi-kcal4-4.10.5-1.1.mga3
lib64akonadi-contact4-4.10.5-1.1.mga3
akonadi-kde-4.10.5-1.1.mga3
lib64akonadiprotocolinternals1-1.9.1-2.mga3
akonadi-1.9.1-2.mga3
lib64akonadi-calendar4-4.10.5-1.1.mga3

I had mariadb 5.5.33a, i will confirm if this happen with mariadb-5.5.28 too
viewtopic.php?f=215&t=117889&start=15

The same problem has occurred in the android tablet.
After some days the calendar came back, so it seems to be a generic dysfunction and not a KDE problem