What version do you have installed or is it trying to install?
Setting up base-config (2.53.10.1) ...Template #30 in /var/lib/dpkg/info/base-config.templates does not contain a 'Template:' line
dpkg: error processing base-config (--configure): subprocess post-installation script returned error exit status 9 Errors were encountered while processing: base-config E: Sub-process /usr/bin/dpkg returned an error code (1)