I'm receiving the following error in the cups error_log after libgs was updated to 9.26:
D [09/May/2019:11:19:22 -0400] [Job 6927] Filetype: PDF
D [09/May/2019:11:19:22 -0400] [Job 6927] Storing temporary files in /tmp
D [09/May/2019:11:19:22 -0400] [Job 6927] PID 28996 (/usr/lib/cups/filter/pdftopdf) exited with no errors.
D [09/May/2019:11:19:22 -0400] [Job 6927] GPL Ghostscript 9.26: Unrecoverable error, exit code 1
D [09/May/2019:11:19:22 -0400] [Job 6927] Process is dying with \"Unable to determine number of pages, page count: -1
D [09/May/2019:11:19:22 -0400] [Job 6927] \", exit stat 3
D [09/May/2019:11:19:22 -0400] [Job 6927] Cleaning up...
D [09/May/2019:11:19:22 -0400] [Job 6927] PID 28997 (/usr/lib/cups/filter/foomatic-rip) stopped with status 3.
D [09/May/2019:11:19:22 -0400] [Job 6927] prnt/backend/hp.c 919: ERROR: null print job total=0
D [09/May/2019:11:19:22 -0400] [Job 6927] PID 28998 (/usr/lib/cups/backend/hp) exited with no errors
Some clarification. I'm using ubuntu 18.04 with an HP Laserjet 500 MFP 570dn... two servers, two of the same printer, and the same issue. It appears to have occured after the following unattended upgrade:
Upgrade: libgs9:amd64 (9.26~dfsg+ 0-0ubuntu0. 18.04.8, 9.26~dfsg+ 0-0ubuntu0. 18.04.9) , ghostscript:amd64 (9.26~dfsg+ 0-0ubuntu0. 18.04.8, 9.26~dfsg+ 0-0ubuntu0. 18.04.9) , ghostscript-x:amd64 (9.26~dfsg+ 0-0ubuntu0. 18.04.8, 9.26~dfsg+ 0-0ubuntu0. 18.04.9) , libgs9-common:amd64 (9.26~dfsg+ 0-0ubuntu0. 18.04.8, 9.26~dfsg+ 0-0ubuntu0. 18.04.9)