I cannot open any odt documents, I have windows 10 and could open them a few days ago

computer does circle for a few seconds then it disappears & nothing happens

Do you leave your computer running all the time, for multiple days, or shut it down after each use? If you leave it on, there might be a LibreOffice process hanging in memory that needs to go away via a reboot or Task Manager End Task. Otherwise, it’s hard to say for sure what’s going on.