There are 3 map modes:
1. 2D pointing north
2. 2D travel direction
3. 3D

System creates a menu then add clicable items in it:
CreateMenu(...);

AddMenuItem(0, "Pointing Norh", ...);
SetOnClickProc(0, point_north_click_proc, ...);

AddMenuItem(1, "Travel Direction", ...); SetOnClickProc(1, travel_dir_click_proc, ...);

AddMenuItem(2, "Perspective", ...);
SetOnClickProc(2, perspective_click_proc, ...);

ShowMenu(...);

When you select item, the apropiate clic procedure is called.
Click procedure for Point North looks like this:

turn_ON_point_north_mode(...);
turn_OFF_travel_dir_mode(...);
turn_OFF_perspective_mode(...);
RedrawMap(...);

Click procedure for 'Travel Direction' and 'Perspective' modes looks similar.

Each click procedure enable mode you selected, then disable two othre modes.
So 3D mode works in v26.09 and works after downgrade to v26. Unless you select 'Travel Direction' or 'Pointing North'.

Instead of adding another line of code we decided the easier solution was to just modify the two available options. adding a line of code can be risky, modifying a line was the easier path.

He had a post in one of the other threads.

Martin