How do I make underscores visible again in Eclipse?

Question

After upgrading my workstation from Ubuntu 14.04 to Ubuntu 16.04 I found that all the underscore _ characters in my C and C++ code were invisible withing the Eclipse editor. This means that function_name and Class_Name started displaying as function name and Class Name; although the _ character was still clearly there based on the syntax highlighting and the results of pasting into gedit.

Answer 1

In ubuntu 16.04 we had same problem with Monospace 14, changing size fixed the problem (i.e. 15 in our case)