I Can't Install GNU/IceCat

It's not supposed to be using GDebi. GDebi is for installing deb files, the link in Abrowser for IceCat is a reference to a package in the repo. The default program that apt links are opened with is Apturl-gtk, but it seems installing GDebi screws that up.

Deb files? I thought Abrowser installed it via APT, but OK.

Try this instead of GDebi to install them:
-CD to the directory of the deb files
-Execute "sudo dpkg -i [DEB FILE]"

If installation still doesn't work, you can try installing with the source/using binaries at http://ftp.gnu.org/gnu/gnuzilla/31.2.0/

EDIT: Above beat me to the punch, and has a better solution than I.

sudo apt-get install icecat

Don't download some random .deb for something that's in the repo!

Created a bug report:

https://trisquel.info/en/issues/12944

You can either just do something like apt-get install icecat instead of clicking on the link, or you can uninstall GDebi. Both of these work, though the former is a lot simpler.

A bit of a technicality, but it's GNU IceCat rather than GNU/IceCat (since IceCat is a GNU package, "GNU IceCat" rightly imples that IceCat is from GNU (well, the GNU project). "GNU Linux" would wrongly imply that Linux is from the GNU project (it isn't).

Linux-libre, on the other hand, is a GNU project, so GNU Linux-libre is correct. Parabola, on the other hand, uses "GNU/Linux-libre" to mean that it's the GNU operating system, with Linux-libre as the kernel.

I can't access the add-on page in IceCat. In Abrowser it worked fine but in IceCat I just see an explanation of what add-ons are and that I'll be able to see them when I get an internet connection. I tried to intall some add-ons from Firefox add-ons web page, but I would prefer to use IceCat's add-on page since it only contains free software.