The SQLite database file sb_modules.php of Sitebuilder site is empty.Is there a reason why the sqlite database can become empty?
We have not faced any issues in Parallels Plesk Sitebuilder 4.5 that cause corruption of SQLite database file. But empty file sb_modules.php-journal might be created from time to time if the site is published into NFS share. Please refer to this KB article for the details:
You may resolve the problem if switch to Parallels Presence Builder 11 (former Parallels Plesk Panel 4.5) where SQLite database is not used by sites. Here you may find more details about Parallels Web Presence Builder 11: