A few weeks ago, Fujifilm acknowledged compatibility issues of various Fujifilm software with MacOS Catalina. Fujifilm is working to fix it, and they released updates on November 14 here, on November 28 here, December 5 here and January 6 here.
The next fix is for Fujifilm X RAW Studio:
FUJIFILM X RAW STUDIO – MAC
The software update Ver.1.8.1 incorporates the following issue:
The compatibility with macOS 10.15.2 is added.
The phenomenon with macOS 10.15.2 is fixed that the connection between the application and a camera cannot be established or it doesn’t recognize a camera. Upgrade the macOS to the latest version (macOS 10.15.3 or newer).
*When FUJIFILM X RAW STUDIO starts first time with the macOS 10.15.3 or newer, the dialog below to encourage the access to “Photos” will appear. Click the “OK” to accept the access. Otherwise, Mac cannot be connected with a camera.
*In case X RAW STUDIO starts with a camera connected, a dialog below to encourage the access to “Removable volume”, “Documents folder” and so on can appear. Click the “OK” to accept the access. Otherwise, Mac cannot be connected with a camera.
Download link for FUJIFILM X RAW STUDIO (MAC)