The new "software centre" won't run after my upgrade to 16.04 last night. Trying it from the unity bar - nothing happens. I read that it should be running gnome's software manager. Trying from the command line - if I got the command right, gives this result
$ gnome-software
(gnome-software:5748): Gs-WARNING **: failed to open plugin /usr/lib/gs-plugins-9/libgs_plugin_xdg_app_reviews.so: /usr/lib/gs-plugins-9/libgs_plugin_xdg_app_reviews.so: cannot open shared object file: No such file or directory
Timeout was reached
I had the same problem after a fresh install and it started working after I killed the process in System Monitor.
I had the same problem. I installed all the updates under System Settings -> Details -> Overview -> Install Updates (Button in the bottom right corner. Ignore if it says System Up-To-Date) and rebooted my PC 3 times (ie: install updates then reboot, install updates then reboot, install updates then reboot, this was straight after a fresh install). Then finally the Software Centre began to work.