Ubuntu Software -> All section is empty

Is it OK now?

If sudo apt-get update && sudo apt-get upgrade followed by a restart doesn't fix the issue, I would suggest:

sudo apt-get dist-upgrade
Restart. If that doesn't help, you could also try backing up then deleting a folder in your home directory associated with the program. First, in Terminal or other CLI:

killall gnome-software
Then

mv ~/.local/share/gnome-software{,-BAK}
Reopen Ubuntu Software. (If needed, you can always undo the removal of the gnome-software folder and restore the backup: rm -r ~/.local/share/gnome-software && mv ~/.local/share/gnome-software{-BAK,})

Finally, if none of this works for you, I would be interested to know the output of:

find /etc/apt/ -name '*.list' -ls -exec cat {} \;
This is a list of all your allowed sources (sources are the repositories that contain the available software to download).

Although I can't think of any reason why you'd have nothing in sources.list, it's also the only explanation I can think of as to why nothing shows up as available in Ubuntu Software after trying all the normal troubleshooting steps.

https://get-9apps.com https://vidmate-apk.in https://get-cartoonhd.com

Try installing the old software-center from the commandline:

sudo apt install software-center
Or try installing synaptic

sudo apt install synaptic

sudo apt install software-center
Or try installing synaptic

sudo apt install synaptic

I tried this @Barry Allen and it worked

Thank you so much for your reply and helping me fixing the issue

Regards.
https://get-mxplayer.in & https://get-mxplayer.in/download/

Thank you so much for your reply and helping me fixing the issue