LibreOffice 7.1 runs on macOS Big Sur, so download it here and carry on with your work.
LibreOffice has much better support for modern operating systems, and many other features too, such as OOXML export, an updated NotebookBar user interface, a cloud-based version and much more. (OpenOffice’s last major release – 4.1 – was back in 2014.) One solution is to install LibreOffice, a more actively developed successor project. If you accept this notice, your choice will be saved and the page will refresh. By accepting, you will be accessing content from YouTube, a service provided by an external third party. Please confirm that you want to play a YouTube video.