The Essential Forms installation program may not have been able to determine the location where your saved clients are stored, and reset the data path to the default location. Open Essential Form, click Configure>Data Directory, either click the drop-down arrow to select a stored data path or click Browse and navigate to the location where the shared network data folder resides. Select that data folder, click OK, then click Use this directory. The program should prompt you to restart it. Reopen Essential Forms and you should see your clients/matters/forms. You can verify the location Essential Forms is configured to use as its data directory by clicking View, then System Information and looking at the third line Data under Directories.

If you now see your clients, but still get a "forms out of date" notice when you launch the program you might need to run the latest JC Update (efinstaller.exe) one more time. Or, possibly try running the Update (efinstaller.exe) from a station with admin permissions.