Overview:
Upon dataloading Account Territory records with the Align Dataloader, the following error occurs:
Account Territory Failed to Upsert. Reason: Missing required parameter [name__v].
Root Cause:
The issue is caused by a custom field located in the Account object. This custom field is used as an identifier instead of the ID or External ID to match on existing records.
Solution:
Using custom fields as identifiers is currently not supported with the Align Dataloader.
The field should be removed or Vault Loader needs to be used for dataloading as a solution.
Related Documentation:
Align Help Documentation: Integrations and Data Loading