I'm trying to import TASKS related to opportunities from one Salesforce org to another using Data Loader.
I have done Excel VLookkups on all Id Values, and all related objects/records are in place on the target org. So, the import CSV includes opportunityId, AccountId, OwnerId from the target org.
I'm getting an error for all records- 'invalid cross reference id'.
I'd like to know which of the related objects does DataLoader use to match records, or what other issue might be behind this error.