How do i recover a file replaced by another

When I opened Libre today, a window opened saying the file in question had to be searched for or refreshed or some similar thing. It turns out The Damnation, my story, the finished version was replaced with the one in this window, an early just begun version. Is there any way to get the finished version back?

Did you save the “restored” version over the old file? What is the modification time of the file now (shown in your file manager)? How do you know that the file actually contained the information you expect (i.e., have you opened the closed file before so that you saw that the data was actually there)?

The dialog you refer to should only pop up when the file is either corrupt, or there was a problem last time you worked with it, so that it wasn’t closed properly. What happened?