When installing icedtea

when installing icedtea web plugin:

installArchives() failed: Selecting previously unselected package icedtea-plugin.
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Preparing to unpack .../icedtea-plugin_1.5.1-1ubuntu1_all.deb ...
Unpacking icedtea-plugin (1.5.1-1ubuntu1) ...
Setting up icedtea-netx:amd64 (1.5.1-1ubuntu1) ...
update-alternatives: warning: forcing reinstallation of alternative /usr/lib/jvm/java-7-openjdk-amd64/jre/bin/itweb-settings because link group itweb-settings is broken
update-alternatives: warning: not replacing /usr/share/man/man1/itweb-settings.1.gz with a link
update-alternatives: warning: forcing reinstallation of alternative /usr/lib/jvm/java-7-openjdk-amd64/jre/bin/itweb-settings because link group itweb-settings is broken
update-alternatives: warning: not replacing /usr/share/man/man1/itweb-settings.1.gz with a link
update-alternatives: error: alternative path /usr/lib/jvm/java-8-openjdk-amd64/jre/bin/javaws doesn't exist
dpkg: error processing package icedtea-netx:amd64 (--configure):
 subprocess installed post-installation script returned error exit status 2
dpkg: dependency problems prevent configuration of icedtea-7-plugin:amd64:
 icedtea-7-plugin:amd64 depends on icedtea-netx (= 1.5.1-1ubuntu1); however:
  Package icedtea-netx:amd64 is No apport report written because the error message indicates its a followup error from a previous failure.
No apport report written because the error message indicates its a followup error from a previous failure.
not configured yet.

dpkg: error processing package icedtea-7-plugin:amd64 (--configure):
 dependency problems - leaving unconfigured
dpkg: dependency problems prevent configuration of icedtea-plugin:
 icedtea-plugin depends on icedtea-7-plugin; however:
  Package icedtea-7-plugin:amd64 is not configured yet.

dpkg: error processing package icedtea-plugin (--configure):
 dependency problems - leaving unconfigured
Errors were encountered while processing:
 icedtea-netx:amd64
 icedtea-7-plugin:amd64
 icedtea-plugin
Error in function:
Setting up icedtea-netx:amd64 (1.5.1-1ubuntu1) ...
update-alternatives: warning: forcing reinstallation of alternative /usr/lib/jvm/java-7-openjdk-amd64/jre/bin/itweb-settings because link group itweb-settings is broken
update-alternatives: warning: not replacing /usr/share/man/man1/itweb-settings.1.gz with a link
update-alternatives: warning: forcing reinstallation of alternative /usr/lib/jvm/java-7-openjdk-amd64/jre/bin/itweb-settings because link group itweb-settings is broken
update-alternatives: warning: not replacing /usr/share/man/man1/itweb-settings.1.gz with a link
update-alternatives: error: alternative path /usr/lib/jvm/java-8-openjdk-amd64/jre/bin/javaws doesn't exist
dpkg: error processing package icedtea-netx:amd64 (--configure):
 subprocess installed post-installation script returned error exit status 2
dpkg: dependency problems prevent configuration of icedtea-7-plugin:amd64:
 icedtea-7-plugin:amd64 depends on icedtea-netx (= 1.5.1-1ubuntu1); however:
  Package icedtea-netx:amd64 is not configured yet.

dpkg: error processing package icedtea-7-plugin:amd64 (--configure):
 dependency problems - leaving unconfigured
dpkg: dependency problems prevent configuration of icedtea-plugin:
 icedtea-plugin depends on icedtea-7-plugin; however:
  Package icedtea-7-plugin:amd64 is not configured yet.

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