Cannot insert duplicate key row in object '[table]' with unique index '[index]'
FAQs > Error Messages > Cannot insert duplicate key row in object '[table]' with unique index '[index]'
You may encounter the following error when attempting to reverse invoices:
![](../__attachments/403931331/image-20200519-143043.png?inst-v=c01b8f8f-1817-42b2-84a2-5646cf6df4de)
Delete any attachments from the invoice in order to address this error. Doing so will potentially allow users to subsequently reverse the invoice without issue.