CLP 320N not working anymore: SPL-C ERROR

[cris]

Suddenly my CLP 320N (connected via LAN) started to print blank pages with the following error:

SPL-C ERROR - Please use the proper driver
    POSITION : 0x0 (0)
    SYSTEM : src_5.47/xl_image
    LINE : 629
    VERSION : SPL-C 5.47 01-15-2010

Up until now the SULD driver worked perfectly.

I've tried to remove/reinstall the SULD driver several times, trying different versions of the driver1 and driver2: nothing helped.

Printing works again (although with bad quality) if I select the Foomatic/foo2qpdl driver.

I'm not sure if this might have something to do with a CUPS upgrade:
I'm using Debian Testing and CUPS version is 2.2.10-4 .

Thank you in advance.

[bchemnet]

I suggest trying to revert your CUPS package to the previously installed verison (e.g., using snapshot.debian.org, although you may need multiple packages) to see if the printer works again.  If so, then it is a bug in CUPS and should be reported through the Debian bug reporter.

[bchemnet]

This problem is related to the CUPS issue reported here:
https://github.com/apple/cups/issues/5562

The gist is that CUPS is making changes that are not compatible with the Samsung drivers.  CUPS 2.2.11 has recently been patched to restore working behavior for Samsung printers, but there is no guarantee that will remain true.  Debian inherited the problematic change in 2.2.10-4 and it may remain as of 2.2.10-6.  If you are using a Debian-based distribution and still have this problem, report it to the bug tracker and reference the CUPS issue above.

This is all related to a complete change in the way that CUPS handles printer drivers, as described here:
https://www.cups.org/blog/2018-06-06-demystifying-cups-development.html

The gist is that printers that do not use IPP, and/or that use custom drivers such as the Samsung driver, and at risk of no longer working after CUPS 2.3 is released (although they will likely continue working for some unknown amount of time after the initial release).  Some of the newer Samsung-branded printers support IPP, so will not necessarily be affected by the changes.  I do not know what the long-term implications are for continuing to provide this repository and the associated drivers.