Error: the same key has already been added
An attempt to import Contributions from an online giving source, results in the following error:
The system cancelled the import due to the following issue: An item with the same key has already been added.
Try importing your contributions again. If the system continues to cancel the import, please contact Customer Success.
If you are using an online giving provider which uses our generic import format, the issue is most likely that the Online Giving company has assigned the same "Unique" ID to all Contributions. Delete the data in column J (Ext Contrib ID) and it will import.
If you are using a company like OSV or our MyOwnGiving, the error message indicates that you have already imported some or all of the contributions included on the file. Those contributions must be removed from the file before you can import it.