How to fix corrupted package cache in ubuntu

Question

Whenever I try to install any new package in Ubuntu 16.04 , it ends up with the following error message

The package cache file is corrupted

I've tried the commands sudo apt-get update and sudo apt-get upgrade but they also fail. It shows:

sudo apt-get update
Get:1 http://download.virtualbox.org/virtualbox/debian xenial InRelease [7,882 B]
Ign:2 http://dl.google.com/linux/chrome/deb stable InRelease                   
Hit:3 http://dl.google.com/linux/chrome/deb stable Release                     
Ign:1 http://download.virtualbox.org/virtualbox/debian xenial InRelease        
Get:4 http://download.virtualbox.org/virtualbox/debian xenial/contrib amd64 Packages [988 B]
Get:5 http://download.virtualbox.org/virtualbox/debian xenial/contrib i386 Packages [998 B]
Hit:6 http://security.ubuntu.com/ubuntu xenial-security InRelease              
Ign:7 http://ppa.launchpad.net/chris-lea/node.js/ubuntu xenial InRelease       
Hit:9 http://in.archive.ubuntu.com/ubuntu xenial InRelease                     
Get:10 http://download.virtualbox.org/virtualbox/debian xenial/non-free amd64 Packages [14 B]
Get:11 http://in.archive.ubuntu.com/ubuntu xenial-updates InRelease [94.5 kB]  
Get:12 http://ppa.launchpad.net/noobslab/apps/ubuntu xenial InRelease [17.6 kB]
Get:13 http://download.virtualbox.org/virtualbox/debian xenial/non-free i386 Packages [14 B]
Get:14 https://deb.opera.com/opera-developer stable InRelease [2,592 B]        
Get:15 https://deb.opera.com/opera-developer stable/non-free amd64 Packages [1,813 B]
Hit:16 http://ppa.launchpad.net/webupd8team/java/ubuntu xenial InRelease       
Hit:17 http://in.archive.ubuntu.com/ubuntu xenial-backports InRelease          
Ign:18 http://ppa.launchpad.net/chris-lea/node.js/ubuntu xenial Release        
Get:19 http://ppa.launchpad.net/noobslab/apps/ubuntu xenial/main amd64 Packages [6,956 B]
Get:20 http://in.archive.ubuntu.com/ubuntu xenial-updates/main amd64 Packages [132 kB]
Get:21 http://ppa.launchpad.net/noobslab/apps/ubuntu xenial/main i386 Packages [6,948 B]
Get:22 http://ppa.launchpad.net/noobslab/apps/ubuntu xenial/main Translation-en [3,780 B]
Ign:23 http://ppa.launchpad.net/chris-lea/node.js/ubuntu xenial/main amd64 Packages.diff/Index
Ign:24 http://ppa.launchpad.net/chris-lea/node.js/ubuntu xenial/main i386 Packages.diff/Index
Ign:25 http://ppa.launchpad.net/chris-lea/node.js/ubuntu xenial/main all Packages.diff/Index
Get:26 https://deb.opera.com/opera-developer stable/non-free i386 Packages [1,813 B]
Ign:27 http://ppa.launchpad.net/chris-lea/node.js/ubuntu xenial/main Translation-en_IN
Get:28 http://in.archive.ubuntu.com/ubuntu xenial-updates/main i386 Packages [130 kB]
Ign:29 http://ppa.launchpad.net/chris-lea/node.js/ubuntu xenial/main Translation-en.diff/Index
Ign:30 http://ppa.launchpad.net/chris-lea/node.js/ubuntu xenial/main amd64 DEP-11 Metadata.diff/Index
Ign:31 http://ppa.launchpad.net/chris-lea/node.js/ubuntu xenial/main DEP-11 64x64 Icons.diff/Index
Ign:32 http://ppa.launchpad.net/chris-lea/node.js/ubuntu xenial/main amd64 Packages
Ign:33 http://ppa.launchpad.net/chris-lea/node.js/ubuntu xenial/main i386 Packages
Ign:34 http://ppa.launchpad.net/chris-lea/node.js/ubuntu xenial/main all Packages
Ign:27 http://ppa.launchpad.net/chris-lea/node.js/ubuntu xenial/main Translation-en_IN
Ign:35 http://ppa.launchpad.net/chris-lea/node.js/ubuntu xenial/main Translation-en
Get:36 http://in.archive.ubuntu.com/ubuntu xenial-updates/main Translation-en [51.8 kB]
Ign:37 http://ppa.launchpad.net/chris-lea/node.js/ubuntu xenial/main amd64 DEP-11 Metadata
Ign:38 http://ppa.launchpad.net/chris-lea/node.js/ubuntu xenial/main DEP-11 64x64 Icons
Ign:32 http://ppa.launchpad.net/chris-lea/node.js/ubuntu xenial/main amd64 Packages
Get:39 http://in.archive.ubuntu.com/ubuntu xenial-updates/main amd64 DEP-11 Metadata [129 kB]
Ign:33 http://ppa.launchpad.net/chris-lea/node.js/ubuntu xenial/main i386 Packages
Ign:34 http://ppa.launchpad.net/chris-lea/node.js/ubuntu xenial/main all Packages
Ign:27 http://ppa.launchpad.net/chris-lea/node.js/ubuntu xenial/main Translation-en_IN
Ign:35 http://ppa.launchpad.net/chris-lea/node.js/ubuntu xenial/main Translation-en
Ign:37 http://ppa.launchpad.net/chris-lea/node.js/ubuntu xenial/main amd64 DEP-11 Metadata
Ign:38 http://ppa.launchpad.net/chris-lea/node.js/ubuntu xenial/main DEP-11 64x64 Icons
Ign:32 http://ppa.launchpad.net/chris-lea/node.js/ubuntu xenial/main amd64 Packages
Ign:33 http://ppa.launchpad.net/chris-lea/node.js/ubuntu xenial/main i386 Packages
Ign:34 http://ppa.launchpad.net/chris-lea/node.js/ubuntu xenial/main all Packages
Get:40 http://in.archive.ubuntu.com/ubuntu xenial-updates/main DEP-11 64x64 Icons [103 kB]
Ign:27 http://ppa.launchpad.net/chris-lea/node.js/ubuntu xenial/main Translation-en_IN
Ign:35 http://ppa.launchpad.net/chris-lea/node.js/ubuntu xenial/main Translation-en
Ign:37 http://ppa.launchpad.net/chris-lea/node.js/ubuntu xenial/main amd64 DEP-11 Metadata
Ign:38 http://ppa.launchpad.net/chris-lea/node.js/ubuntu xenial/main DEP-11 64x64 Icons
Ign:32 http://ppa.launchpad.net/chris-lea/node.js/ubuntu xenial/main amd64 Packages
Ign:33 http://ppa.launchpad.net/chris-lea/node.js/ubuntu xenial/main i386 Packages
Ign:34 http://ppa.launchpad.net/chris-lea/node.js/ubuntu xenial/main all Packages
Ign:27 http://ppa.launchpad.net/chris-lea/node.js/ubuntu xenial/main Translation-en_IN
Ign:35 http://ppa.launchpad.net/chris-lea/node.js/ubuntu xenial/main Translation-en
Ign:37 http://ppa.launchpad.net/chris-lea/node.js/ubuntu xenial/main amd64 DEP-11 Metadata
Ign:38 http://ppa.launchpad.net/chris-lea/node.js/ubuntu xenial/main DEP-11 64x64 Icons
Ign:32 http://ppa.launchpad.net/chris-lea/node.js/ubuntu xenial/main amd64 Packages
Ign:33 http://ppa.launchpad.net/chris-lea/node.js/ubuntu xenial/main i386 Packages
Ign:34 http://ppa.launchpad.net/chris-lea/node.js/ubuntu xenial/main all Packages
Ign:27 http://ppa.launchpad.net/chris-lea/node.js/ubuntu xenial/main Translation-en_IN
Ign:35 http://ppa.launchpad.net/chris-lea/node.js/ubuntu xenial/main Translation-en
Ign:37 http://ppa.launchpad.net/chris-lea/node.js/ubuntu xenial/main amd64 DEP-11 Metadata
Ign:38 http://ppa.launchpad.net/chris-lea/node.js/ubuntu xenial/main DEP-11 64x64 Icons
Err:32 http://ppa.launchpad.net/chris-lea/node.js/ubuntu xenial/main amd64 Packages
  404  Not Found
Err:33 http://ppa.launchpad.net/chris-lea/node.js/ubuntu xenial/main i386 Packages
  404  Not Found
Ign:34 http://ppa.launchpad.net/chris-lea/node.js/ubuntu xenial/main all Packages
Ign:35 http://ppa.launchpad.net/chris-lea/node.js/ubuntu xenial/main Translation-en
Get:41 http://in.archive.ubuntu.com/ubuntu xenial-updates/universe amd64 Packages [69.3 kB]
Ign:37 http://ppa.launchpad.net/chris-lea/node.js/ubuntu xenial/main amd64 DEP-11 Metadata
Ign:38 http://ppa.launchpad.net/chris-lea/node.js/ubuntu xenial/main DEP-11 64x64 Icons
Get:42 http://in.archive.ubuntu.com/ubuntu xenial-updates/universe i386 Packages [66.5 kB]
Get:43 http://in.archive.ubuntu.com/ubuntu xenial-updates/universe Translation-en [32.2 kB]
Get:44 http://in.archive.ubuntu.com/ubuntu xenial-updates/universe DEP-11 64x64 Icons [27.3 kB]
Fetched 886 kB in 16s (52.5 kB/s)                                              
Reading package lists... Error!
W: GPG error: http://download.virtualbox.org/virtualbox/debian xenial InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY A2F683C52980AECF
W: The repository 'http://download.virtualbox.org/virtualbox/debian xenial InRelease' is not signed.
N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.
N: See apt-secure(8) manpage for repository creation and user configuration details.
W: There is no public key available for the following key IDs:
A2F683C52980AECF  
W: http://dl.google.com/linux/chrome/deb/dists/stable/Release.gpg: Signature by key 4CCA1EAF950CEE4AB83976DCA040830F7FAC5991 uses weak digest algorithm (SHA1)
W: http://dl.google.com/linux/chrome/deb/dists/stable/Release.gpg: Signature by key 3B068FB4789ABE4AEFA3BB491397BC53640DB551 uses weak digest algorithm (SHA1)
W: The repository 'http://ppa.launchpad.net/chris-lea/node.js/ubuntu xenial Release' does not have a Release file.
N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.
N: See apt-secure(8) manpage for repository creation and user configuration details.
E: Failed to fetch http://ppa.launchpad.net/chris-lea/node.js/ubuntu/dists/xenial/main/binary-amd64/Packages  404  Not Found
E: Failed to fetch http://ppa.launchpad.net/chris-lea/node.js/ubuntu/dists/xenial/main/binary-i386/Packages  404  Not Found
E: Some index files failed to download. They have been ignored, or old ones used instead.
E: Unable to parse package file /var/lib/apt/lists/ppa.launchpad.net_chris-lea_node.js_ubuntu_dists_xenial_main_binary-amd64_Packages (1)
E: Unable to parse package file /var/lib/apt/lists/ppa.launchpad.net_chris-lea_node.js_ubuntu_dists_xenial_main_binary-i386_Packages (1)
E: Unable to parse package file /var/lib/apt/lists/ppa.launchpad.net_chris-lea_node.js_ubuntu_dists_xenial_main_binary-all_Packages (1)
E: Unable to parse package file /var/lib/apt/lists/ppa.launchpad.net_chris-lea_node.js_ubuntu_dists_xenial_main_i18n_Translation-en (1)
W: You may want to run apt-get update to correct these problems
E: The package cache file is corrupted

How do I fix this?

Answer 1

The first problem is this repository: https://launchpad.net/~chris-lea/+archive/ubuntu/node.js/. As you see there are not xenial packages. To fix this open Software & Updates at Other Software tab and remove this ppa or click Edit and change xenial to utopic if you need the package that this repository contains.

The second problem is the virtualbox ppa. Remove the ppa as before and follow the instructions here: https://www.virtualbox.org/wiki/Linux_Downloads (possibly you forgot to add the key signature).