Restore Documents After Failed Shutdown

Do you want to: Ask a how-to question / Report a bug
For bug reports, provide the steps to reproduce and if possible a minimal demo of the problem:

  • Execute command documentserver-prepare4shutdown.sh
    • Get “Preparing for shutdown, it can take a lot of time, please wait… Done”
  • Stop OnlyOffice Docker container
  • Start an updated OnlyOffice instance

Old Document Server version: 6.2.2 (with Docker)
New Document Server version: 6.4.0 (without Docker)
Connector version: 7.1.2 (Nextcloud OnlyOffice App)
DMS (platform) version: Nextcloud 21.0.4
OS: Ubuntu 20.04
Browser version: Firefox 93.0/Chromium 94.0
GitHub Issue: https://github.com/ONLYOFFICE/DocumentServer/issues/1467

Some document were not closed and saved correctly, there are empty or not updated.
My question NOT why documentserver-prepare4shutdown.sh does not work, how can I solved it? The old App_Data directory and database still exist. Can I migrate the old database into the new database?