Please choose the appropriate version: ZeusDraw1.3.4 will not run on El Capitan or later and ZeusDraw1.4.1 will not run on Yosemite or earlier. The two versions have identical features and the same license works for either.
ZeusDraw1.3.4 for OS X 10.10 (Yosemite) and earlier
ZeusDraw1.4.1 for OS X 10.11 (El Capitan) and later
ZeusDraw1.4.1 fixes a crash and some problems with brushes that occur when ZeusDraw1.4.0 is run on OS X 10.12 (Sierra)