There are premade object shapes that have almost everything needed. Under the Object Tab in the Terrain Editor there is an Available Shapes list box. As an example, look for lafld0. This is for a large field and will have all the hangers, ammo, fuel, radar, etc. needed. If you want to add this field, first place checkmarks for Grid and for Snap in the Terrain Window Options in the lower left of the Terrain Editor. This will show you the terrain tiles and let you select the exact center of a tile. Click the center of a tile to place a red plus where you want the file to go. Click the Add Shape/Group button to place the field. An Object Properties window will open. Set the Object Type to Group Master and give it a file and zone number. Then click Ok to close the Object Properties window. Fields need map rooms and they normally get them using the town0 object. Find town0 in the Available Shapes list box. Click the center of a different tile and click the Add Shape/Group button. The town will also be a Group Master with the same field and zones number you used for the field. Vehicle fields are an exception to using towns because they have there own map rooms.
If you want to save yourself some time, make your new field and town a Shape Group. You will click and hold the left mouse key to drag a box around your town and field. Start with the town and drag just past the center of the field. If you do it properly, both the town and field will be selected and the red plus will be in the center of the filed. (Remember the Snap checkbox?) The location of the red plus will determine where the group will be place in relation to the red plus used during the add shape process. Click the Save Shape Group button in the Selection List box to open the Group Name window. Give the group a unique name like Tlafld and click OK. You will have to close and reopen the Terrain Editor to refresh the Shape Group list box to get your new group to show. Now when you need a large field and town just select your new Shape Group and click the Add Shape/Group button. This time a Select Field window will open where you just have to choose a field and zone number.
The game crashing with your new map (called a terrain) can be cause by a lot of things. Obviously there is something wrong with your terrain. Open the Terrain Editor and go to the Objects Tab. There is an Obj Report button that will open and Object Report window. Click the Check Terrain button and see what comes up. Fix any problems and check for errors again until there are no errors found. Save your changes, close and reopen the Editor and then build your terrain. Copy your new version into the Aces High folder and see if the game will run.
You can not edit a premade map unless you have all those source files.
Good Luck.
