Preparing to unpack .../squid-common_3.5.12-1ubuntu7_all.deb ...
De-configuring squid3 (3.3.8-1ubuntu16.2), to allow removal of squid3-common (3.3.8-1ubuntu16.2) ...
invoke-rc.d: policy-rc.d denied execution of stop.
Unpacking squid-common (3.5.12-1ubuntu7) ...
Selecting previously unselected package squid.
Preparing to unpack .../squid_3.5.12-1ubuntu7_amd64.deb ...
Unpacking squid (3.5.12-1ubuntu7) ...
Replacing files in old package squid3 (3.3.8-1ubuntu16.2) ...
Setting up libecap3:amd64 (1.0.1-3ubuntu3) ...
Setting up libltdl7:amd64 (2.4.6-0.1) ...
Setting up squid-common (3.5.12-1ubuntu7) ...
Setting up squid (3.5.12-1ubuntu7) ...
Removing obsolete conffile /etc/squid3/msntauth.conf ...
invoke-rc.d: policy-rc.d denied execution of restart.
Removing obsolete conffile /etc/init.d/squid3 ...
Removing obsolete conffile /etc/init/squid3.conf ...
dpkg: dependency problems prevent processing triggers for ufw:
 ufw depends on python3; however:
  Package python3 is not configured yet.
 ufw depends on python3:any (>= 3.3.2-2~); however:
  Package python3 is not configured yet.

dpkg: error processing archive /var/cache/apt/archives/squid3_3.5.12-1ubuntu7_all.deb (--unpack):
 dependency problems - leaving triggers unprocessed
Errors were encountered while processing:
 /var/cache/apt/archives/squid3_3.5.12-1ubuntu7_all.deb
Error in function: 


A fatal error occurred 

Please report this as a bug and include the files 
/var/log/dist-upgrade/main.log and /var/log/dist-upgrade/apt.log in 
your report. The upgrade has aborted. 
Your original sources.list was saved in 
/etc/apt/sources.list.distUpgrade. 

SystemError: E:Sub-process /usr/bin/dpkg returned an error code (1) 



Could not install the upgrades 

The upgrade has aborted. Your system could be in an unusable state. A 
recovery will run now (dpkg --configure -a). 

Please report this bug in a browser at 
http://bugs.launchpad.net/ubuntu/+source/ubuntu-release-upgrader/+filebug 
and attach the files in /var/log/dist-upgrade/ to the bug report. 
installArchives() failed 

Setting up mime-support (3.59ubuntu1) ...
Installing new version of config file /etc/mime.types ...
dpkg: dependency problems prevent configuration of squid3:
 squid3 depends on squid3-common (= 3.3.8-1ubuntu16.2); however:
  Package squid3-common is not installed.
  Version of squid3-common on system, provided by squid-common:all, is <none>.
 squid (3.5.12-1ubuntu7) breaks squid3 (<< 3.5.12-1ubuntu1~) and is awaiting trigger processing by another package.
  Version of squid3 to be configured is 3.3.8-1ubuntu16.2.

dpkg: error processing package squid3 (--configure):
 dependency problems - leaving unconfigured