Erreur lors de l'utilisation d'apt-get

Je ne suis pas très expert en linux. Je n'utilise Ubuntu que depuis quelques mois. Récemment, je suis confronté à la même erreur chaque fois que j'essaie d'accomplir une tâche (principalement des tâches apt-get). Par exemple ici, j'essaye d'installer htop pour mon but et c'est l'erreur que je reçois. Il semble que l'erreur se produise à cause de rsync, mais je ne suis pas sûr de l'erreur ni de la façon dont je peux m'en débarrasser.

sudo apt-get install htop
Reading package lists... Done
Building dependency tree       
Reading state information... Done
htop is already the newest version.
0 upgraded, 0 newly installed, 0 to remove and 5 not upgraded.
1 not fully installed or removed.
After this operation, 0 B of additional disk space will be used.
Do you want to continue? [Y/n] y
Setting up rsync (3.1.1-3ubuntu0.15.04.1) ...
insserv: warning: script 'K01vpnagentd_init' missing LSB tags and overrides
insserv: warning: script 'vpnagentd_init' missing LSB tags and overrides
insserv: Starting vpnagentd_init depends on rc.local and therefore on system facility `$all' which can not be true!
insserv: Starting vpnagentd_init depends on rc.local and therefore on system facility `$all' which can not be true!
insserv: Starting vpnagentd_init depends on rc.local and therefore on system facility `$all' which can not be true!
insserv: There is a loop between service vpnagentd_init and rc.local if started
insserv:  loop involving service rc.local at depth 7
insserv:  loop involving service vpnagentd_init at depth 1
insserv: Starting vpnagentd_init depends on rc.local and therefore on system facility `$all' which can not be true!
insserv: exiting now without changing boot order!
update-rc.d: error: insserv rejected the script header
dpkg: error processing package rsync (--configure):
 subprocess installed post-installation script returned error exit status 1
Errors were encountered while processing:
 rsync
E: Sub-process /usr/bin/dpkg returned an error code (1)

J'ai aussi essayé d'utiliser sudo dpkg --configure -aet j'obtiens l'erreur suivante

Setting up rsync (3.1.1-3ubuntu0.15.04.1) ...
insserv: warning: script 'K01vpnagentd_init' missing LSB tags and overrides
insserv: warning: script 'vpnagentd_init' missing LSB tags and overrides
insserv: Starting vpnagentd_init depends on rc.local and therefore on system facility `$all' which can not be true!
insserv: Starting vpnagentd_init depends on rc.local and therefore on system facility `$all' which can not be true!
insserv: Starting vpnagentd_init depends on rc.local and therefore on system facility `$all' which can not be true!
insserv: There is a loop between service vpnagentd_init and rc.local if started
insserv:  loop involving service rc.local at depth 7
insserv:  loop involving service vpnagentd_init at depth 1
insserv: Starting vpnagentd_init depends on rc.local and therefore on system facility `$all' which can not be true!
insserv: exiting now without changing boot order!
update-rc.d: error: insserv rejected the script header
dpkg: error processing package rsync (--configure):
 subprocess installed post-installation script returned error exit status 1
Errors were encountered while processing:
 rsync

Ce serait vraiment utile si quelqu'un pouvait indiquer ce que je devrais faire pour supprimer cette erreur. J'utilise Ubuntu 15.04. Merci de votre aide.

Je voudrais supprimer rsync, tenter de résoudre le problème lié au script vpnagentd_init et réinstaller rsync.

1) Supprimer rsync en utilisant sudo apt-get remove rsync

2) Éditez /etc/init.d/vpnagentd_init et insérez les balises LSB suivantes.

### BEGIN INIT INFO
# Provides: vpnagentd_init
# Required-Start: $remote_fs $syslog
# Required-Stop: $remote_fs $syslog
# Default-Start: 2 3 4 5
# Default-Stop: 0 1 6
# Short-Description: Start Cisco vpn agent daemon at boot time
# Description: Cisco vpn agent daemon (believe installed by company ssl client)
### END INIT INFO

Source: http://forums.debian.net/viewtopic.php?f=30&t=53192#p575807

3) Installez rsync en utilisant sudo apt-get install rsync

Si tout se passe bien, vous ne devriez voir aucun de ces avertissements vpnagentd_init et le script de post-installation de rsync devrait s'exécuter sans erreur.