sudo apt-get purge unity-webapps-service
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following extra packages will be installed:
  libedit2
The following packages will be REMOVED:
  libunity-webapps0* unity-webapps-common* unity-webapps-service*
  xul-ext-unity* xul-ext-websites-integration*
The following packages will be upgraded:
  libedit2
1 upgraded, 0 newly installed, 5 to remove and 52 not upgraded.
1 not fully installed or removed.
Need to get 0 B/86.7 kB of archives.
After this operation, 1,261 kB disk space will be freed.
Do you want to continue? [Y/n] y
Selecting previously unselected package libedit2:amd64.
dpkg: warning: files list file for package 'unity-webapps-service' missing; assuming package has no files currently installed
dpkg: warning: files list file for package 'python3-sip' missing; assuming package has no files currently installed
dpkg: warning: files list file for package 'unity-lens-applications' missing; assuming package has no files currently installed
dpkg: warning: files list file for package 'mysql-common' missing; assuming package has no files currently installed
dpkg: warning: files list file for package 'update-inetd' missing; assuming package has no files currently installed
dpkg: warning: files list file for package 'libgcrypt11:i386' missing; assuming package has no files currently installed
dpkg: warning: files list file for package 'libsox-fmt-alsa:amd64' missing; assuming package has no files currently installed
dpkg: unrecoverable fatal error, aborting:
 files list for package 'libedit2:amd64' is not a regular file
E: Sub-process /usr/bin/dpkg returned an error code (2)