System.DmlException: Insert failed. First exception on row 0; first error: DUPLICATE_VALUE, duplicate value found: <unknown> duplicates value on record with id: <unknown>. The above error is triggered in the database layer and caused by a trigger or workflow outside of your main code of block that is bubbling this exception. This is rather difficult to track down especially if you are unfamiliar with the code, I am sharing my procedure in the hopes this saves you time - if you find this helpful drop me a line or follow me on twitter @danielsokolows . This error is caused by unique field constraint on the object, so the first step is to examine the object and locate the API names of all unique fieds. You can do this through SF direclty 'Setup < Customize < <object being inserted> < Fields' or by downloading the `src/objects` metadata information and searching for <unique> ; I preffer the latter and actually download ALL matadata i...