Open a terminal window.
Type: cd 'Quick and Easy Web Builder' (or wherever you have stored it)
Type: ls -al Q*
Then tell us what is displayed. My system is using Kubuntu 18.10 and it works fine for me, my screen shows this:
the dates may be different on yours but the execution bits and sizes should be the same.-rwxrwxr-x 1 brian brian 36993176 Feb 5 09:04 qnewb
-rw-r--r-- 1 brian brian 158 Jul 28 2016 qnewb.desktop
-rw-r--r-- 1 brian brian 3990774 Jul 9 2018 qnewb.pdf
-rw-rw-r-- 1 brian brian 55770 May 8 2018 qnewb.png
Brian.