Please note: this issue was fixed in v.1.0.12 (Apr 2021). Below instructions are still valid for all preceding versions of SPX-GC.
When a prebuilt binary version of SPX-GC is downloaded, extracted, made executable and run the first time the config.json file and folders LOG and DATAROOT are generated to current user's home directory and not to the to the installation directory.
This root cause of the issue is that on Mac the home directory is the default directory when an "open" command is executed in the operating system. This folder is being reported to SPX-GC at startup and it generates files to that folder.
This is an #issue-3 in source the code repository.
Use command line!
At the moment, the only reliable way to execute the binary program on Mac is by using the Terminal and NOT by double clicking on the SPX-GC icon in Finder.
Navigate to your SPX-GC directory with cd command, such as cd /myApps/spxgc/
run SPX-GC from command line with ./SPX-GC_macos64
Open your browser (Chrome recommended) and load up the SPX-GC from the URL shown in the Terminal.