With the release of macOS Catalina 10.15, Apple introduced new safety and security features. If you upgrade a Mac system to this release, some WatchGuard software might not install or work correctly.
WatchGuard software support for macOS Catalina 10.15, as of 11 November 2019:
Note - For compatibility with macOS Catalina 10.15, applications must use the current macOS software architecture standards. These new applications require macOS High Sierra 10.13 or later.
* The Mobile VPN with SSL v12.5.2 software is currently available on the software download page for Fireware v12.5.1 Update 1. Users will not be able to download Mobile VPN with SSL v12.5.2 from the Firebox until the release of Fireware v12.5.2 later this year.