Comment 2 for bug 1370602

I had the same error.
The manager, localhost and to_localhost definitions are built-in in later squid-versions...
Simply restart your system after the relase-upgrade and remove the following lines from your squid.conf:

acl manager proto cache_object
acl localhost src 127.0.0.1/32 ::1
acl to_localhost dst 127.0.0.0/8 0.0.0.0/32 ::1

If that doesn't help, here are the steps I did before removing the lines in squid.conf but I don't think these are necessary:
apt-get remove squid3
apt-get autoremove
apt-get install squid3