A book has been requested and is showing as Delivery Confirmation Not Available.  Is there any way to get Quick Credit?  I can't use Printable Postage, either, since DC isn't available.

I do not send books without DC; I would rather not send with USPS DC, and have thought about cancelling the transaction.  Should I PM the requestor and ask them to verify their address in the PBS system?

Even if they verify their address, I don't think it will change for this order, it wouldn't take effect until their next order after it was entered into the system. You might try waiting a couple hours, it might be that the DC system is having a problem for a moment. I've seen people post every so often that they can't put DC on, and then a couple hours later, sometimes not till the next day, someone posts that it's working again.

it is possible it is a new subdivision and it just takes time for it to be updated in the system.  you could PM and ask them if they are in a new area or why they would have this message pop up.  It is always possible that it was a quirk in the system.

I have never sent a book with DC and have not had a problem as of yet.  I wouldn't worry about it and just send the book this one time without DC.

I get that sometimes when trying to print postage. Usually if I log out for a while and try again later it works.