Why would my Libre Office files on my desktop suddenly not open?

These files were made from the Writer component in English, but don’t know the version and can’t open to find out. I’ve had it downloaded for about a year. It suddenly won’t open any files or LibreOffice itself, although it will open LibreOffice folders on the desktop. Everything else opens as usual. When I click on the files, the circle goes around for 2-3 seconds, then shuts off and file doesn’t open. Any ideas how to fix or why this is happening?

First of all - still, what exactly doesn’t work? Try to run LibreOffice itself. If it’s OK then try to open your broken files with “Open file” command or drag-and-drop files into LibO window. The result will determine your further steps.

I have been using Libre Office for several months and suddenly I can not open any Libre Office files. Libre Office itself will not open. I am in the middle of writing a novel and this is a huge problem. What is happening? How can I fix it?

Because LO is presumably no longer the default program for .odt files.

Re-allocate in Windows Control Panel Default Programs.