Saving error - linux

Few days I work on big document 50 pages, with registered changes.
Some times was screen about error with converter, but program still work.
some time after it when I save file - proces going ok, but no file i saved!!! It is terrible when you work with big file.

OS version: Linux Mint 21
App version: 7.2
Downloaded from: deb package from onlyoffice website

Hello @jacko
We need additional information and opportunity to reproduce the issue for proper troubleshooting.
If the issue reproduces again, please make screenshots and provide us with a file where you face this situation.