Solved
I have just updated to STM32 cubeIDE V1.4.0 It asked for ST Link Server for debugging. I downloaded and installed successfully on my Mac Catalina 10.15.6 But cube IDE still asks ST Link Server and tells I should download it from www.st.com
Have you updated your STM32CubeIDE product from 1.x.x release to 1.4.0 or brand new install ?
If update "only" I would have a try to perform a fresh brand new install taking care to install ALL proper material from installer.
