I'm currently using EasyABC 1.3.7.7 for Mac, running OS 10.14.6 Mojave, the latest versions of both.
Apple will not be updating Mojave in the future, but switching over to OS Catalina on which 32-bit software will no longer work; only 64-bit software will work.
EasyABC is ony 32-bit software so will not run on OS Catalina.
For the moment I will keep running OS Mojave, but at some future time (when all the bugs have been ironed out), I will probably need to upgrade to OS Catalina, for security updates as much as anything.
As far as I can see via on-line searching, there is not a 64-bit ABC editor available for Mac yet. Does anyone know differently?