问题解决：Ubunt16.04系统无法Update错误解决。

Ubuntu 16.04:Problemexecuting scripts APT::Update::Post-Invoke-Success 'if /usr/bin/test -w/var/cache/app-info -a -e /usr/bin/appstreamcli; then apapstreamcli refresh> /dev/null; fi'

Reading package lists... Done

E: Problem executing scriptsAPT::Update::Post-Invoke-Success

'if /usr/bin/test -w /var/cache/app-info-a -e /usr/bin/appstreamcli;

then appstreamcli refresh > /dev/null;

fi'

E: Sub-process returned anerror code

在运行sudo apt-get update时出现如上信息，解决方法如下：

#sudo pkill-KILL appstreamcli

#wget -P/tmp https://launchpad.net/ubuntu/+archive/primary/+files/appstream_0.9.4-1ubuntu1_amd64.deb https://launchpad.net/ubuntu/+archive/primary/+files/libappstream3_0.9.4-1ubuntu1_amd64.deb

#sudo dpkg-i /tmp/appstream_0.9.4-1ubuntu1_amd64.deb/tmp/libappstream3_0.9.4-1ubuntu1_amd64.deb

执行完上述命令之后再次运行sudo apt-get update就不会再出现上面的错误。