The Map Editor is a separate tool and can’t be accessed through the game. To access the Map Editor, open your Steam client, click on LIBRARY → TOOLS and double-click Stronghold Crusader 2 Map Editor to start the download.  Once the download has completed double-click again on Stronghold Crusader 2 Map Editor to load the Map Editor.

 

IMPORTANT: You must install the Stronghold Crusader 2 game before you install the map editor.