I'm not sure where to report this, so please reassing to the
appropriate package.

In Trixie my HP ScanJet was working properly, I could scan using
simple-scan.

Some weeks ago I upgraded to Testing/Forky. Now I wanted to scan. The
scanner is detected, (e.g. in simple-scan), but when I want to
connect, scanning fails because a connection to the scanner could not
be established.

Also in the display of the scanner the computer is not found.

The cabeling for the scanner is unchanged.

helge@twentytwo:~$ scanimage -L
device `v4l:/dev/video0' is a Noname Hauppauge WinTV-HVR5525 virtual device
device `hpaio:/usb/HP_ScanJet_Pro_4500_fn1?serial=CN0C3D904B' is a Hewlett-Packard HP_ScanJet_Pro_4500_fn1 all-in-one

helge@twentytwo:~$ LC_ALL=C scanimage > pic.pnm
Output format is not set, using pnm as a default.
scanimage: sane_start: Invalid argument
helge@twentytwo:~$ file pic.pnm
pic.pnm: empty

root@twentytwo:~# lsusb
…
Bus 003 Device 009: ID 03f0:5405 HP, Inc HP ScanJet Pro 4500 fn1
…

root@twentytwo:~# sane-find-scanner

  # sane-find-scanner will now attempt to detect your scanner. If the
  # result is different from what you expected, first make sure your
  # scanner is powered up and properly connected to your computer.

  # No SCSI scanners found. If you expected something different, make sure that
  # you have loaded a kernel SCSI driver for your SCSI adapter.

found possible USB scanner (vendor=0x03f0 [HP], product=0x5405 [HP ScanJet Pro 4500 fn1]) at libusb:003:009
  # Your USB scanner was (probably) detected. It may or may not be supported by
  # SANE. Try scanimage -L and read the backend's manpage.

  # Not checking for parallel port scanners.

  # Most Scanners connected to the parallel port or other proprietary ports
  # can't be detected by this program.

Hi, Helge,

This may have the same origin as #1137654 [hplip cannot download plugin].
According to

https://developers.hp.com/hp-linux-imaging-and-printing/binaryplugintable

that model seems to require a binary plugin for scanning. Did you find
any message about plugins?

Thorsten, please consider using an updated hp+hplip gpg key in
debian/upstream/signing-key.asc for hplip package. It will be installed with
the package and should fix #1137654, and will also help to know if this is
the same problem or not.

Thanks for your contribution to Debian,

Hello Agustin,
sorry for the belated reply, I just returned from Summer vacation
(without computer :-)).

Am Mon, Jul 20, 2026 at 06:44:18PM +0200 schrieb Agustin Martin:
simple-scan: common/utils.c 140: validate_plugin_version() Plugin version[3.22.10] mismatch with HPLIP version[3.26.4]

This refers to the same plugin version as in #1137654.

This would be really great.

Besides getting my scanner working, is there anything else I
could/should try in the meantime?

https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1137654#10
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1137654#15
provide some workaround steps. Should I try (some of) them as well?

Greetings

          Helge

Hello Augustin,
it seems like there is no action on this bug report, unfortunately.

Am Mon, Jul 20, 2026 at 06:44:18PM +0200 schrieb Agustin Martin:

So I followed the instructions in #1137654. For the record, the public
key for verification can be found here:
https://developers.hp.com/hp-linux-imaging-and-printing/hplipDigitalCertificate.html

To install the plugin, I did *not* call hp-plugin. As already
discovered in #1137654 this fails.

Instead I obtained "hplip-3.26.4-plugin.run". As I was able to verify
the authenticity with the key obtained above, I executed it (as
non-root!) and it installed the plugin without problem.

And now scanning works again!

I CC'ed 1137654, as this might make printer installation possible as
well.

That would be perfect! Using #1137654 with my instructions above
hopefully make this possible.

Greetings

         Helge