software installation - can't install any apps

I have Ubuntu 16.04 on my computer. In the last few days, I can't install any new apps from however I try to install it (.deb files, Software Center, dash). I can't even update the apps I installed before encountering this problem.

Can anybody help me?

Run the following commands:

rm ~/.local/share/gnome-software/*
sudo apt-get upgrade gnome-software

sudo apt-get update

This will solve the problem