Thanks Phaedrux
Now that I have looked, and had a skim read of the requirements, I realize that to upgrade to V3 is not a task to be undertaken lightly. I think I'll wait until there is a definite reason to upgrade.
Thanks for the link.
Dave

Thanks Phaedrux I'll have a look. I was thinking that in future firmware upgades may need whatever this version needs.

Should I now investigate / make the changes necessary to upgrade to firmware V3? What is involved, is there a tutorial? I'd better pay attention this time.

Printing away nicely now....
Thanks again.
Dave

I downloaded both files that you suggested, then installed the firmware and web control. Voila! it seems to be fixed. My temperature values are as I'd expect, the error for the bed has gone and I am able to turn the heaters on and see their values change.
Thanks a million.

Thanks Danal
I tried uploading and installing firmware V2.03 just then, which didn't fix things.
Tool 0
T0
undefined
n/a
n/a
0
0
Bed
Heater 0
off
error
0

I'll try your suggestion and let you know what happens.

Would the Config file have been altered by the new firmware?

Here is my current config.g config.g file, I think it's the only copy I have.

@bearer said in Firmware rollback or other solution:

it would certainly help to know what you thought was the latest firmware, and what version you previously used. and if you upgraded all the various parts duet firmware, wifi firmware, duet web control etc.

I think I have only upgraded on part of the firmware, are there other parts I should have upgraded, or should I proceed and try to roll it back to an earlier version?

Thank you so much Jens, Phaedrux, deckingman and bearer for your replies / suggestions, it seems to be a very helpful forum.
Currently this is displayed in the settings part of the web interface under software information.

Firmware Name: RepRapFirmware for Duet 2 WiFi/Ethernet
Firmware Electronics: Duet WiFi 1.02 or later
Firmware Version: 3.0 (2020-01-03b3)
WiFi Server Version: 1.23
Web Interface Version: 1.22.6

I should have but didn't make a note of the old (working) firmware version, but given that nothing has physically changed on the machine, or within my settings etc, should be still there somewhere? Right?