5) before the "Getting updates" disappears hit "Close"
(gpk-update-viewer:15476): Gtk-CRITICAL **: gtk_main_quit: assertion `main_loops != NULL' failed
is in the terminal and window is not closed. Disable the "Close" button till "There are no updates available" is shown or is list of update types displayed, please.
This bug report is very old and based on a version not supported anymore. By upgrading to a newer version of PackageKit you could receive bug fixes and new functionality. You may need to upgrade your Linux distribution to obtain a newer version of PackageKit.
Please feel free to reopen this bug if the problem still occurs with the latest version.