The latest official release comes with the following improvements and bug fixes.
As you might know Apple plans to discontinue support for 32 bit apps and is actively warning users of the impending change, with a warning message notifying the user that the app will eventually not be compatible with the operating system unless it is updated.
Support for 64-bit installers has already been added in the previous release, InstallBuilder version 18.4. In this release we have been focused on fixing issues related to this new architecture.
In addition to that, InstallBuilder 18.5 also adds support for Java 10 version detection.