Hi.
I just dowloaded 4.1 beta and all menus are grayed.
I'm on Mac High Sierra 10.13.1 Beta (17B46a)
Regards
See https://github.com/archimatetool/archi/issues/304
Yes, this Archi beta is meant to show the problem in High Sierra 10.13.1 beta. We wait to see what Apple will do for 10.13.1 GM. There will be a workaround in Eclipse backported to Eclipse 4.7.1 very soon. Either way it will be fixed soon.
But as a general point, OS X betas are not officially supported.