Thonny keeps an on-line record of what the latest firmware is, which I believe is at the URL mentioned in the pop-up of the OP -
https://raw.githubusercontent.com/thonny/thonny/master/data/rpi-pico-firmware.json
That appears to be as I would expect it and the link to the the '.uf2' file appears to be correct and available. That isn't however the latest release so that could be the issue. My own tools are confused about the existence of any 1.22.1 version, the development branch latest being 1.22.0-161, aka 1.23.0-preview-161, and neilgl's Thonny identified 1.22.1 as latest release even though not specified in the linked file above.
The error pop-up doesn't detail what it couldn't figure out so it may be worth asking the author.
An alternative to loading firrmware through Thonny is to download the latest release or latest versions of the '.uf2' files directly from MicroPython and copying them to the Pico or Pico W in BOOTSEL mode -
Pico : https://micropython.org/download/rp2-pico
Pico-W : https://micropython.org/download/rp2-pico-w
https://raw.githubusercontent.com/thonny/thonny/master/data/rpi-pico-firmware.json
That appears to be as I would expect it and the link to the the '.uf2' file appears to be correct and available. That isn't however the latest release so that could be the issue. My own tools are confused about the existence of any 1.22.1 version, the development branch latest being 1.22.0-161, aka 1.23.0-preview-161, and neilgl's Thonny identified 1.22.1 as latest release even though not specified in the linked file above.
The error pop-up doesn't detail what it couldn't figure out so it may be worth asking the author.
An alternative to loading firrmware through Thonny is to download the latest release or latest versions of the '.uf2' files directly from MicroPython and copying them to the Pico or Pico W in BOOTSEL mode -
Pico : https://micropython.org/download/rp2-pico
Pico-W : https://micropython.org/download/rp2-pico-w
Statistics: Posted by hippy — Thu Feb 22, 2024 2:37 pm