I was trying to use a get .debs website the other day and with a lot of frustration of firefox saying
Firefox does not have the correct protocol to open this file [.apt] I finally figured out that I did not have
apt-url installed on kUbuntu.
This can be fixed by simply opening a terminal window and typing:
sudo apt-get install apturl
Then restart firefox. Go to download another .deb / .apt file and when it asks you what you would like to use to open the file browse to
/usr/bin and pick whatever installs your programs.
Posted on September 17, 2009