RPI-errors-dat

The Repository "***" does not have a Release file. unable to update

/etc/apt/sources.list.d/

deb http://archive.raspberrypi.org/debian/ stretch main ui
# Uncomment line below then 'apt-get update' to enable 'apt-get source'
deb-src http://archive.raspberrypi.org/debian/ stretch main ui

deb http://raspbian.raspberrypi.org/raspbian/ stretch main contrib non-free rpi to deb http://legacy.raspbian.org/raspbian/ stretch main contrib non-free rpi

https://raspberrypi.stackexchange.com/questions/143053/my-rpi-wont-update

/etc/apt/sources.list

/etc/sources.list.d/raspi.list