You need Java installed. I used the Open JRE. Some places on the web say you need the Oracle version, but it works for me with the Open JRE and IcedTea:
sudo apt-get install openjdk-8-jre icedtea-8-plugin
That’s all you need to get the meeting to work, but…
Missing i386 Libraries
But you won’t be able to share screens without a bunch of missing i386 libraries. The WebEx plugin is 32-bit, so you need to install some libraries that aren’t installed by default.
Check to see if you’re missing libraries by going into
~/.webex/ and then into a sub-directory whose name is all digits and underscores. Once there, run:
ldd *.so | grep "not found" | cut -f1 -d' ' | tr -d '\t' | uniq
I got about a dozen missing libraries on a relatively new install of Ubuntu 16.04. You may get different results, depending on what’s been installed on your system since you initially installed Ubuntu 16.04.
I installed the following packages [updated with suggestions from readers] (fewer than a dozen, because some packages pull in multiple libraries as dependencies):
sudo apt-get install libxmu6:i386 sudo apt-get install libgtk2.0-0:i386 sudo apt-get install libpangox-1.0-0:i386 sudo apt-get install libpangoxft-1.0:i386 sudo apt-get install libxtst6:i386 sudo apt-get install libasound2:i386 sudo apt-get install libxv1:i386
If you check again with the above
ldd command, the only library you should still be missing is
libjawt.so. This library doesn’t seem to be needed.