So i installed fresh Ubuntu 16.04.1 and did a software update from software updater. The update was completed successfully and then i rebooted. After the reboot, i did a 'sudo apt update' and it showed 6 packages can be updated. Then i opened software center and in its update tab its showing those 6 updates as 'os update'. But the included separate software updater app still showing 'your computer is up to date'. Clearly this is a bug. I would like to know, is it safe to install those updates via software center? Is this bug reported? Thanks in advance.
open up a terminal and issue these commands
sudo apt-get update sudo apt-get upgrade
this will give you an update ... same as the GUI version you speak of ... with added bonus of displaying details if things go awry ... after doing above if you still have an issue please update your question with a paste from the screen output