NOTE: As of ModelSim 18.0 it appears that it is not necessary to install freetype-2.4.12 in Step-3 anymore! It seems to be working fine with the builtin freetype-2.8.10 in Fedora-28. ModelSim Starter ...

The free version of ModelSim is a 32-bit binary and therefore requires certain 32-bit libraries in order to work correctly. For Ubuntu, install the following packages ...