I want to point out that since version 3.5.4 of IceCat installation directory is named /usr/lib/icecat, instead of /usr/lib/icecat-x.x.x, so in file /etc/apparmor.d/abstractions/ubuntu-browsers you need to add this string: /usr/lib/icecat/icecat Ux,
I want to point out that since version 3.5.4 of IceCat installation directory is named /usr/lib/icecat, instead of /usr/lib/ icecat- x.x.x, so in file /etc/apparmor. d/abstractions/ ubuntu- browsers you need to add this string: lib/icecat/ icecat Ux,
/usr/