I think I found a bug in the new Xcode 16 version that caused it to fail on macOS 10.15 and 11 (for developers who stumble upon this: Xcode for some reason linked QuicklookUI.framework which is not available on these older macOS versions)
It should be solved now in 4.661, but you will need to redownload via folivora.ai - Great Tools for your Mac!