Hi!
I recently had this issue:
I changed the customer on the estimate no problem (based on project), then went to invoice, unlinked the estimate, which clears all of your totals and descriptions, edited the customer tot he correct customer, added 1 generic line that was the total of my invoice (because it will not let you close an invoice for $0). Once you save the "updated invoice" open the invoice again and re-link the estimate (if it doesn't auto populate you can find under "manage icon > suggestions > suggested transactions" & look for the estimate number. Once you click the estimate, it will re-add all of the totals & descriptions again. Be sure to delete the generic line you added to the blank invoice (it will not have the linked icon at the end of the line) & save!
