I'm running Win10 and having a right faf on getting new maps into the game..............I can only find the 'ingame' .ter maps in the 'this pc > local disk (c:) > ProgramData > esimgames > steel beasts > maps'
The ProgramData folder is hidden, so I've just made a shortcut to it on my desktop.
I've dropped the new maps (all single file *.ter files) into this maps folder but the game wont even see them, let alone open them.
Seems weird that the maps are in a hidden folder that has to be 'unhidden' before you can see them..............