First of all, it looks like you're using version 5.0.1, which is many months out of date. I would recommend updating to our latest version 5.1.2, as that includes a long list of improvements and bug fixes which are beneficial.
When you install the software, it's normal that the OS may display a message like the one you posted. As long as you downloaded the software directly from the Simplify3D website, you can click "Run Anyway" to proceed with the installation.
If you have any other questions about installing the software on these enterprise systems, please feel free to email our team directly at the link below:
https://www.simplify3d.com/contact-us/