This item has been identified as an outstanding known issue. A workaround is provided until the issue is officially fixed.
When running an import action in a model, if it completes with failures, the "Details" tab of the "Import Completed" screen may present the error message "Unable to display failed import rows".
From the "Details" tab, click "Save Failure Log..." in the top right of the window. This will download the failure details as a CSV file.
If this workaround is not suitable in your use case, please contact Support at firstname.lastname@example.org.
Internal Reference: CORESRV-6875