Russell,
After trying sooooo many things, the only way Cookie 5 launches is via Terminal app by double clicking the executable inside the MacOS folder. But once you quite Terminal, Cookie quits as we’ll.
Katie
[attachment=104]

[attachment=103]I tried EVERYTHING. I am a pretty knowledgable user and have to conclude that it is a app issue.

See Screenshot

I restarted many times. I tried uninstaller, cache cleaners and nothing. I even tried your latest trial version after uninstalling. Even your trial .dmg does not have a proper icon (see attachment) which leads me to believe that there might be issues with permissions, code signatures, etc. 
[attachment=102]

Cookie 5.8.5 no longer opens after updating to macOS v10.13.6 (High Sierra). Pop window alert states:
The application “Cookie 5” can’t be opened.
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Moreover, the app icon is a generic one.
Please fix this!