Thanks, Mark. In the elegance stakes, that solution scores zero, I'm afraid! Fortunately, by updating MP Navigator to v4.0.5 and reinstalling the IJ Network Tool in its latest version, all problems with my MG 6150 have been overcome. Took me a couple of hours to sort that out and I would have hoped for an auto-update from Canon, to be honest, but the job's done, thankfully. Hopefully this might help other sufferers.
If you've updated to the most current version of the software from our site at http://Canon.us/SupportCF and you're still having problems, we recommend reaching out to support for further troubleshooting and options. Printer support at Canon USA can be reached at 1-800-OK-CANON (800-652-2666) weekdays from 10am to 10pm (ET). If you're outside of the USA, click HERE for support options.
12/05/2023: New firmware updates are available.
09/26/2023: New firmware updates are available.
08/18/2023: Canon EOS R5 C training series is released.
07/31/2023: New firmware updates are available.
05/18/2023: New firmware updates are available.
03/30/2023: New firmware updates are available.