only those contacts with events
My G3 contacts app force closes too. I figured out that it is due to the events (Birthdays, Anniversary) in the contact. You can view the contact just fine, but once you edit it, the app force closes. You can also create a new contact and try to add a new event, the app will force close.
However, I find this problem a little odd. The app only started to force close after I had done a factory reset to fix my wifi problems. Prior to the factory reset, I was able to edit some contacts with events.
I hope that I'm wrong, and there is a way to fix this problem quickly. I'm not sure LG is good at fixing stuff.