The files are shown, but can’t open them
The files are shown
Shown where? In a history window, like in “I remember that you have worked with these files recently; here’s saved screenshots of them”?
If you just upgraded to the latest 6.3 you might have to just clear your recent history and go to the directory where the files are and load them via the “File/Open” from within the LO program or using whatever file manager you use Explorer/Nemo etc. You may need to reset the file association by right clicking on the LO file and going into the properties