All contacts disappeared! Plus phone log gone..

[moonlander]

So I woke up this morning and suddenly ALL my contacts were gone. My phone log was wiped as well. I did not install any apps or alter any settings last night. Can someone shed some light on this problem? 

I've checked the filters, that's not the problem (and it shouldn't affect the phone log either, right?)

I've tried closing the "contacts" app and clearing the data, that didn't do it either.

Someone got any idea what happened, how to restore my contacts and/or prevent it from happening again?

Edit:Xperia Z3

[_alexdon_]

Could you boot in safe mode and check again?

http://talk.sonymobile.com/t5/FAQ/How-to-boot-your-phone-into-safe-mode/m-p/348008

Maybe you have a backup or something,don't you do from time to time one?