If you get an error when trying to log into eFileCabinet Client using a regular Windows user account, but you can log in using a Windows administrator account with no errors, this may be due to a Windows security permissions issue. If you get the same message when To resolve, perform the following steps -

Unexpected Error for Windows User:
For Windows Vista, 7, 8, 10
1. Navigate to C:\ProgramData\eFileCabinet and right click on the 5 folder, then go to Properties.
2. Go to the Security tab and select "Edit", then select "Add" in the screen that follows.
3. Type Everyone in the space provided, then select "OK", then check the box for "Full Control" and select OK in the window, and the window that follows.For Windows XP
The same steps will be applied to the 5 Folder found at the following directory: C:\Documents and Settings\All Users\Application Data\eFileCabinet
Unexpected Error for Administrator User:

The explanation for this is a simple one. It means that the Administrator user is already logged in to eFileCabinet on another workstation. Once that session is closed, you can log into in as Administrator again.

However, if you're absolutely certain that the administrator user is logged out, the user session may be stuck.  The only way to fix that is to restart the eFileCabinet Server Service.  You can do that by finding the eFileCabinet System Tray icon located on the server computer and choosing restart.  This will log everyone out of eFileCabinet.