FontLab Studio 5, Fontographer 5 and TypeTool 3 on macOS 10.15 Catalina
macOS 10.15 Catalina drops all 32-bit app support, which means FontLab Studio 5, Fontographer 5, TypeTool 3, and BitFonter 3 for Mac will not run on it — and porting them to 64-bit is not feasible. If you are on Catalina, your options are CrossOver Mac 19 (run the Windows versions via a thin emulation layer), a virtual machine running an older macOS or Windows, or upgrading to the 64-bit FontLab 7.