I am receiving "DUPLICATE_VALUE:Duplicate id specified:000000000000000AAA:-- " when upserting contacts into import wizard for any contact record that I am CREATING brand new.

For any record that was an updated record, all updates worked correctly. Even with two contacts linked to same account ID (one being an update and one being a new contact), I recieved this issue on the contact I was trying to create.

I've been trying to import lists since June and keep getting this error and multiple Salesforce rep's haven't been able to help me. Any ideas?