Visit the official Schneider Electric Exchange forum: https://www.se.com/ww/en/work/support/exchange/ Search for the "Legacy Software" section for community-driven support on SoMachine 4.3.
While waiting for my official download link to process, I actually found a physical CD-RW labeled "SoMachine 4.3 - Do not lose" buried in the client’s maintenance shed. It was scratched, dusty, and unreadable. Schneider Somachine 4.3 Download
To successfully install and run SoMachine 4.3, your engineering PC must meet these specifications (based on the original release notes): Schneider Somachine 4.3 Download