API error on sending to Klipper (Mainsail)

did always work, but now there is an API error on the key?
do not know where to start now?

Could we get a screenshot of the error and maybe a systeminfo bundle?

Do you think the issue is on the OctoPrint or on the Klipper side?

after a view restarts, it works again. will come back if not. thx

Sorry, but Klipper Mainsail has nothing to do with OctoPrint.

Or are you running both side by side?