I have created a content type with a addressfield field but in the configuration field form It doesn't let me set an empty default value. How can I fix it?
Did you run a search on addressfield's issues?
I think this is what you are looking for. Link
The sulotion from the addressfield's issue: "This issue contains a patch using hook_field_presave(). The preferred way is to use hook_field_is_empty(), to determine if an empty/default value should be stored in the database. However, hook_field_is_empty() does not contain info about the field instance settings."