Libre Text Basic Functions Hang Up

Using macbook pro, mid-2010, 8gb, with El Capitan and LibreOffice 5.1.4.2, results in very slow response, beachball spinning for most every day tasks: opening font menu, selecting font type/size, searching text, scrolling with cursor to highlight/select, in the middle of typing. Also, text documents take a long time to open. How can I troubleshoot or resolve problem? I’ve uninstalled and installed various versions over time because I’d really like to use it but no success.