DUPLICATE_VALUE

Example of the full error message:

DUPLICATE_VALUE: duplicate value found: <unknown> duplicates value on record with id: <unknown>

On which products will you see the error?

All Titan products.

Why did you receive this error message?

This is a complex error on the Salesforce side. You tried to push a record from Titan to Salesforce. This operation failed most likely due to a unique field constraint on the object
The above error is triggered in the database layer and caused by a trigger or workflow