CS4 will not run on any macOS version released in the last decade (Catalina or later). It requires "Legacy" systems like OS X Snow Leopard (10.6) or Lion (10.7).
Added support for RED R3D and AVCHD without transcoding. 🍎 The Mac Experience premiere pro cs4 mac
Using CS4 on a Mac in 2008–2010 was a mixed bag for several reasons: CS4 will not run on any macOS version