This issue has been fixed in Empire Express 2.1.
When you try to open Empire Express 2.0 for the first time, you may receive the message “Empire Express can’t be opened because it is from an unidentified developer.” If this happens, do the following:
- Switch to the Finder if necessary.
- Position the mouse pointer on the Empire Express icon.
- Hold down the control key as you press the mouse button. A menu will pop up.
- Choose Open from the menu.
- An alert will ask if you’re sure you want to open it. Click Open.
After doing this, you will be able to open Empire Express in the future just by double-clicking.