Ubuntu apt-get проблемы с обновлением / установкой

У меня проблемы с Ubuntu, работающим на EC2.
Всякий раз, когда я пытаюсь обновить какой-либо пакет, он показывает какой-то журнал и останавливается посередине, а если я снова запускаю процесс обновления, он говорит мне: "Не удалось получить блокировку /var/cache/apt/archives/lock"

# Command Execute #
apt-get install php5-common
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following extra packages will be installed:
  libapache2-mod-php5 php5-cli php5-curl php5-gd php5-mysql
Suggested packages:
  php5-suhosin
The following packages will be upgraded:
  libapache2-mod-php5 php5-cli php5-common php5-curl php5-gd php5-mysql
6 upgraded, 0 newly installed, 0 to remove and 149 not upgraded.
Need to get 0 B/8,103 kB of archives.
After this operation, 4,096 B of additional disk space will be used.

Do you want to continue [Y/n]? y
Reading changelogs... Done

[3]+  Stopped                 apt-get install php5-common

# Error Message #
**==================================================​

**Get:1 Changelog for php5-common 
(http://changelogs.ubuntu.com/changelogs/pool/main/p/php5/php5_5.3.10-1ubuntu3.17/changelog) [201 kB]

php5 (5.3.10-1ubuntu3.17) precise-security; urgency=medium
  * SECURITY UPDATE: denial of service via recursion
    - debian/patches/CVE-2014-8117.patch: lower recursion limit in
      ext/fileinfo/libmagic/softmagic.c.
    - CVE-2014-8117

  * SECURITY UPDATE: denial of service or possible code execution in
    enchant
    - debian/patches/CVE-2014-9705.patch: handle position better in
      ext/enchant/enchant.c.
    - CVE-2014-9705

  * SECURITY UPDATE: arbitrary code execution via use after free in
    unserialize() with DateTime
    - debian/patches/CVE-2015-0273.patch: fix use after free in
      ext/date/php_date.c, added test to ext/date/tests/*.phpt.
    - CVE-2015-0273

  * SECURITY UPDATE: denial of service or possible code execution in phar
    - debian/patches/CVE-2015-2301.patch: fix use after free in
      ext/phar/phar_object.c.
    - CVE-2015-2301
 -- Marc Deslauriers <marc.deslauriers@ubuntu.com>  Mon, 16 Mar 2015 13:59:27 -0400

php5 (5.3.10-1ubuntu3.16) precise-security; urgency=medium
  * SECURITY UPDATE: arbitrary code execution via improper handling of duplicate keys in unserializer
    - debian/patches/CVE-2014-8142.patch: fix use after free in
      ext/standard/var_unserializer.*, added test to
      ext/standard/tests/serialize/bug68594.phpt.
    - CVE-2014-8142

  * SECURITY UPDATE: arbitrary code execution via improper handling of
    duplicate keys in unserializer, additional fix
    - debian/patches/CVE-2015-0231.patch: fix use after free in
      ext/standard/var_unserializer.*, added test to
      ext/standard/tests/strings/bug68710.phpt.
    - CVE-2015-0231

  * debian/patches/remove_readelf.patch: remove readelf.c from fileinfo as
    it isn't used, and is a source of confusion when doing security
    updates.

  * debian/patches/CVE-2014-3710.patch: removed, wasn't needed.
 -- Marc Deslauriers <marc.deslauriers@ubuntu.com>  Fri, 13 Feb 2015 11:53:39 -0500
​php5 (5.3.10-1ubuntu3.15) precise-security; urgency=medium

  * SECURITY UPDATE: denial of service via buffer overflow in mkgmtime()
    - debian/patches/CVE-2014-3668.patch: properly handle sizes in
      ext/xmlrpc/libxmlrpc/xmlrpc.c, added test to
      ext/xmlrpc/tests/bug68027.phpt.
    - CVE-2014-3668

  * SECURITY UPDATE: integer overflow in unserialize()
    - debian/patches/CVE-2014-3669.patch: fix overflow in
      ext/standard/var_unserializer.{c,re}, added test to
      ext/standard/tests/serialize/bug68044.phpt.
    - CVE-2014-3669

  * SECURITY UPDATE: Heap corruption in exif_thumbnail()
    - debian/patches/CVE-2014-3670.patch: fix sizes in ext/exif/exif.c.
    - CVE-2014-3670

  * SECURITY UPDATE: out of bounds read in elf note headers in fileinfo()
    - debian/patches/CVE-2014-3710.patch: validate note headers in
      ext/fileinfo/libmagic/readelf.c.
    - CVE-2014-3710

  * SECURITY UPDATE: local file disclosure via curl NULL byte injection
    - debian/patches/curl_embedded_null.patch: don't accept curl options
      with embedded NULLs in ext/curl/interface.c, added test to
      ext/curl/tests/bug68089.phpt.
    - No CVE number
 -- Marc Deslauriers <marc.deslauriers@ubuntu.com>  Tue, 28 Oct 2014 15:06:12 -0400
(END)**

Команда обновления показывает вышеупомянутый журнал и останавливается и не позволяет ничего делать.
Есть идеи, что не так? заранее спасибо