Their response for completeness' sake:
Thank you for contacting Simplify3D support. I'd be happy to assist you with your install on Fedora. The Fedora developers have decided to handle their version numbering differently than other major distributions. To use the software on Fedora, please download the file linked below, unzip it and copy the resulting file to the Simplify3D install directory (typically /opt/Simplify3D-3.1.1).
https://www.dropbox.com/s/rbs5b3td76x62 ... t.zip?dl=0
After you have this file in the Simplify3D install directory you should then be able to run the included launch script and successfully launch Simplify3D. For example, open a Terminal window and type:
cd /opt/Simplify3D-3.1.1
sudo ./LaunchScript.sh