I have a similar issue as #17 when trying to update:
Downloading http://pkg.8devices.com/kinkan/v1.4/targets/rtkmipsel/rtl8197f/packages/Packages.gz
Updated list of available packages in /var/opkg-lists/openwrt-8devices-rtk_core
Downloading http://pkg.8devices.com/kinkan/v1.4/targets/rtkmipsel/rtl8197f/packages/Packages.sig
Signature check failed.
Remove wrong Signature file.
Downloading http://pkg.8devices.com/kinkan/v1.4/packages/mipsel_24kc/base/Packages.gz
*** Failed to download the package list from http://pkg.8devices.com/kinkan/v1.4/packages/mipsel_24kc/base/Packages.gz
Downloading http://pkg.8devices.com/kinkan/v1.4/packages/mipsel_24kc/8devices_custom/Packages.gz
*** Failed to download the package list from http://pkg.8devices.com/kinkan/v1.4/packages/mipsel_24kc/8devices_custom/Packages.gz
Downloading http://pkg.8devices.com/kinkan/v1.4/packages/mipsel_24kc/luci/Packages.gz
*** Failed to download the package list from http://pkg.8devices.com/kinkan/v1.4/packages/mipsel_24kc/luci/Packages.gz
Downloading http://pkg.8devices.com/kinkan/v1.4/packages/mipsel_24kc/packages/Packages.gz
*** Failed to download the package list from http://pkg.8devices.com/kinkan/v1.4/packages/mipsel_24kc/packages/Packages.gz
Downloading http://pkg.8devices.com/kinkan/v1.4/packages/mipsel_24kc/routing/Packages.gz
*** Failed to download the package list from http://pkg.8devices.com/kinkan/v1.4/packages/mipsel_24kc/routing/Packages.gz
Downloading http://pkg.8devices.com/kinkan/v1.4/packages/mipsel_24kc/telephony/Packages.gz
*** Failed to download the package list from http://pkg.8devices.com/kinkan/v1.4/packages/mipsel_24kc/telephony/Packages.gz
I have a similar issue as #17 when trying to update: