As so often when Apple or Microsoft provide updates for their operating systems, there are incompatibilities with various applications. This also applies to Apple's "macOS Catalina", which has been officially available since October 8.
Users of the Roon software complain in the forum that Roon under Catalina no longer has access to music on an external hard drive. The Roon developers promise to fix the problem, but for the time being do not recommend updating to Catalina. Adobe also warns against incompatibilities of older Photoshop versions with Catalina, whose components such as licensing and installer are still 32-bit. Catalina is the first macOS that only accepts 64-bit applications. So: If in doubt, better don't update right away! The world doesn't end if you work with older versions of an operating system – provided that there are still security updates for them.