Build image 18.06.9 brcm63xx error

When I tried to build image with command "make image" this errors happen:

Collected errors:
 * opkg_install_pkg: Package libjson-c sha256sum mismatch. Either the opkg or the package index are corrupt. Try 'opkg update'.
 * opkg_install_cmd: Cannot install package base-files.
 * opkg_install_pkg: Package odhcpd-ipv6only sha256sum mismatch. Either the opkg or the package index are corrupt. Try 'opkg update'.
 * opkg_install_cmd: Cannot install package odhcpd-ipv6only.
 * opkg_install_pkg: Package ppp-mod-pppoe sha256sum mismatch. Either the opkg or the package index are corrupt. Try 'opkg update'.
 * opkg_install_cmd: Cannot install package ppp-mod-pppoe.
make[2]: *** [Makefile:153: package_install] Error 255
make[1]: *** [Makefile:114: _call_image] Error 2
make: *** [Makefile:193: image] Error 2

18.06.x hasn't been supported for half a decade by now, build issues are to be expected - and it does contain known/ unfixed security issues. Upgrade to a supported version.