Problem solved. Here is what I think happened.

I somehow blocked this contact before I made the update, we had chat minutes before the update. Then update removed all contacts and chat history.

After update with new version I couldn't add this blocked contact and also when this contact wasn't on Mitakuuluu contact list I couldn't unblock it.

Solution was that I installed android version of Whatsapp, there was possible to unblock this contact. Then I removed android Whatsapp and started Mitakuuluu again. And now I was able to add this contact again.