If you've upgraded from an elog 2.x version to an 3.x version, then all entries of a logbook will be moved into subfolder, one for each year.
If you then switch back to the 2.x version of elog, it'll not find any entries.
You can move them back to the folder for the logbook (one directory up) and they'll be found again after the next restart of elog.
I have been using elog for over 10 years. Suddenly my elog installation has changed (probably from a recent update. My /etc/elogd.cfg has changed to the original demo configuration. Even after changing it to my configuration from backup none of the entries for the logbooks apper even though the tabs for the logboos are ther all logbooks are empty. I have looced at the logbook files and the entries seem to be there but are not showing on the web interface. Has something changed? Is there a new location for the logbooks and other files? Is there a change from the 32-bit to the 64-bit version that will cause this. I am running CentOS 7 fully patched and updated. Will there be a CentOS 8 compatible version?