How can I recover an invoice I have mistakingly erased
Hello Ron,
To recover an invoice you have just deleted you can click menu File > Undo Delete Invoice.
To recover an invoice you deleted a while ago, click menu Tools > User Activity, then scroll down until you find the entry starting "Deleted Invoice...".
Double-click on that entry and note the details of the invoice you deleted. Then click menu File > New > Invoice and re-enter those details.
Thanks Mark!