This is a re-post of something that apparently got lost during the period when the site went down. I use an HP Photosmart printer with a usb connection. It worked normally before this update. After the update it stalled and lpstat -t said "Waiting for printer to become available". The jobs stayed in the queue and there were no sounds from the printer indicating that it had received the files. I browsed around and found that this message is sometimes associated with the blacklisted usblp module. Apparently there were earlier versions of cups that didn't do the blacklisting properly so that the driver got attached to the printer before it was blacklisted. I believe that this is now happening again. One thread recommended running the usb backend by hand as a diagnostic. I did so and got: DEBUG: Loading USB quirks from "/usr/share/cups/usb". DEBUG: Loaded 81 quirks. DEBUG: list_devices DEBUG: libusb_get_device_list=11 DEBUG: Failed to detach "usblp" module from 03f0:7511 03f0:7511 is the usb identity of my printer. I do have a blacklist file for the module in /etc/modprobe.d, which I believe cups installed, and lsmod showed that the module was not currently loaded. I rebuilt my kernel without compiling the usblp driver, and cups is now working again. Confusingly, the kernel help for this driver suggests that you *should* build it if you have a usb-connected printer. That advice seems to be badly out of date. -- H Russman