Comment 11 for bug 573853

I get the same error.

home@home-server:~$ sudo /etc/init.d/squid restart
Rather than invoking init scripts through /etc/init.d, use the service(8)
utility, e.g. service squid restart

Since the script you are attempting to invoke has been converted to an
Upstart job, you may also use the restart(8) utility, e.g. restart squid
squid start/running, process 4140
home@home-server:~$ sudo service squid restart
restart: Job failed to restart
home@home-server:~$

Using Ubuntu 32 bit Lucid Lynx and SQUID 2.7.STABLE7