I try to change the configuration of the GPIO as described here.
I use GonfigBlockEditor version 1.3. In the interactive mode there isn’t section GPIO in the list. In batch mode GonfigBlockEditor shows error in the line 1. My config is
setconfig gpio.bootconf "[gpio_83] altfn=-1 dir=out lvl=0"
save gpio
Currently the Config Block Editor does not support the new gpio.bootconf setting. We will publish a new tool recently. Currently, you have to configure this setting in directly in the bootloader. Just enter the bootloader menu and type in the commands there.
Short note about the config block string you are using: Please do not only add the requested changes to the config block but also keep the default string (see also the note in the documentation).