LO constantly hangs trying to open on Catalina (using desktop IMAC). Does not return error message or fail at authentication. It just hangs. Have reloaded program and sys repeatedly. Same result.
Maybe you need to give LibreOffice full disk access from System Preferences > Security & Privacy. See this site on how to do it if you aren’t sure: Explained: What is Full Disk Access & Full Permissions on macOS Mojave .