The PDF button on some sent invoices opened a page with only "The issued invoice PDF is unavailable." This affected invoices sent before Magpie stored a copy of each invoice's PDF, and any invoice whose stored PDF was missing or had changed. The same failure stopped Send again, the Client Portal, the pay page and the app from showing the PDF.
Magpie now checks the PDF when the invoice is opened. If it is missing or was changed, Magpie makes it again from the details saved with the invoice and adds PDF made again to the invoice Activity. For an older invoice with no details saved, the PDF takes the current business details and contact details. If the PDF cannot be made, the invoice page shows the reason under PDF.