When you use the TaxAct Enterprise Edition over a Local Area Network (or LAN), the files that contain your master information, which include preparer information, are kept in the same shared folder as your return files. If you have a network drive, for example designated as "Z," and you put the data folder of your client data, each of the TaxAct programs on each computer are pointed at that location to see the same returns and the same preparer and master information.
If you lose the connection to that network drive, dedicated server, or shared location, the TaxAct programs will revert to the local drive to look for that information. If you have no return files on the local "C:" drive of the computer, or have never backed up your preparer information there, it will appear that all your return files and preparer information are gone.
The same will occur if you move or delete any of the files, including the .dat files that contain program master info, from the shared location.
Windows networking can disconnect for intended or unintended reasons. This is a longstanding and familiar Microsoft problem. It's intended to work as leasing addresses for a temporary period, but indiscriminate disconnects can also occur.
When you find no information in TaxAct, you need to open a Windows Explorer (Windows logo key + E) and make sure the computer has a connection to the other network drive. Then you must select Preparers > Master Information > Directories to open your TaxAct program and make sure it's pointed at that location. For the Client Data Directory Local Data Directory item, you click Browse and navigate to the network drive and the folder you are using for the client data folder.