Interesting. I was pulling the tariff data via a Node-RED node I did a few years ago and that has also started throwing errors. Not sure what has changed!
Something external has changed as I haven’t changed anything on the Pi for ages. In fact I was wondering today if I need to update my system. My EMONCMS is 11.3.0. I haven’t upgraded as when I installed it I modified the Modbus TCP interface for my heat pump and I didn’t want to accidentally overwrite anything. But maybe you have added to the Modbus interface options by now?
Yes, it seems that Octopus is no longer publishing prices for that tariff, and it’s likely that you have been migrated onto a later one. Login to your account and check which tariff you’re actually on now.