I installed v.1.1.1 on a Mac Pro (late 2013 - - - 3.7 GHz Quad-Core Intel Xeon E5, 32GB memory, AMD FirePro D300 2048 MB video card) running macOS 10.13.6.
The download and installation were successful. The installation log shows no problems.
BUT: The program will not load fully or run. No error messages, no crash log. It starts to load and then exits or crashes after the logo icon has appeared on the Dock for about a second.
I had exactly the same experience with a MacBook Pro running a beta version macOS 10.14. Even though the video card was 'unsupported', the earlier version of AI GigaP ran successfully.
Does anyone know how to install the version that 1.1.1 replaced? It was slow on the MacBook, but it worked, and gave very nice results.