Installed theme doesn't show up in Themes

Hi guys. You see, im very new to the whole hosting thing. I am having troubles installing my theme Activello. I tried every method that I could.
I tried uploading it in my wp-content/themes with a .zip file, extracted it, and checked that the file isn’t under nested folders. I changed the permission to 755, but I still can’t see my theme under the Themes menu.
I also tried installing it using FTP… still can’t see the theme. I also tried uploading the theme on the Add New Theme menu, and still got the same results.
Please help me guys.

P.S. I am using Softaculous.