What I mean is that you need to launch BTS with the "Run As Administrator" option even if you have an Adminsitrator-level account. There are several ways to do this. In my case, I chose to create a special shortcut for Age of Ice using the following method.
1) Navigate to your BTS folder in the Explorer.
2) Right-click on the icon for
Civ4BeyondtheSword.exe and drag it somewhere (like the desktop); choose "
Create Shortcut Here" from the menu.
3) Right-click the new shortcut and choose Properties.
4) Switch to the
Shortcut tab then add the following to the end of the
Target box:
(Note there is a space before "mod")
5) Switch to the Compatibility tab and check the option "Run this program as an administrator"
6) Click OK. When you double-click that shortcut, BTS should run in administrator mode (you'll have an extra confirmation first) and automatically load Age of Ice.
Note that another common reason for getting no interface when launching a mod is that there is a conflict with some of your Custom Assets. In that case, you can open up the mod's INI file and set the option.