A bit of history, I worked on the file for a week and according to the characters there were about 60 pages and 90k characters. After that, after a 1-day break from working on it, it simply stopped opening.
You open the file through any function (LibreOffice, the file itself on the computer or directly in LibreOffice Writer) and the application starts and freezes after 1-2 seconds without displaying any errors or something like that. Attempts to find crash logs did not give anything because in the only file in the right dump directory, the characteristics of the systems are simply indicated. From my observations, I can only say that LibreOffice takes 400 MB of RAM and gets up after that.
In addition, a similar file opened in MS office and resaved through it begins to open in Libreoffice, but all the formatting in the document falls off.