All of a sudden the program didn’t open anymore.
“Libre Office does not open, program looks good” must be our new local “SNAFU” variant 
Have you tried to start in safe mode/reset user profile?
Saw another party with the same problem. Solved mine by going to the older stable version. Even that did not want open. Created a shortcut, copied it to the desktop. Then tried to reload. This time a popup came up and said can’t create a desktop shortcut. This happen a few times. I just kept closing the popup. Finally it loaded desktop icon worked and no problem with Libre Office.