When I logged into manager just now there are several strange changes.
Under customers, I no longer see “quantity to deliver”. Under suppliers, I no longer see “quantity to receive”. I have not made any changes to the program. Last time I logged in (14 hours earlier) the program was working like normal.
Another thing that has changed is that I suddenly owe suppliers due to currency exchange loss. This was not the case 14 hours earlier. I always enter the currency equivalent when registering payment in foreign currencies.
What has changed in the program since the last 14 hours? How can I have functionality restored?
I can duplicate a series of apparently related bugs. Quantities to deliver and receive have vanished from the Customers and Suppliers tabs, as @whereskarlo wrote. But they have also been transformed to zero in the Inventory Items tab. I have put this topic into the bugs category.
I am happy to report both bugs are fixed. The customers and suppliers have their columns back for qty to send and receive (and for the inventory tab as well like mentioned by @Tut), and the currency exchange gains/loss have disappeared as amounts due on old purchase invoices. Thanks for the fixes @lubos