I'll assume that you are not double clicking in the Project Map to open the section/elevations or selecting them in Plan and using right click to open.
If that is the case then the solution is to go to "System Preferences" and under Keyboard select "Use F1-F2 keys as standard function keys…"
or if you don't want to change it then you will need to press "Fn key +F3" to open the 3D window.
Eduardo Rolón AIA NCARB AC27 US/INT -> AC08
Macbook Pro M1 Max 64GB ram, OS X 10.XX latest another Moderator
thank you Eduardo i did not now that but it was not my question..
my problem is that it seems that my macbook doesn't convert a 2D floor plan to a 3D model because it cant handle the size of the file while my Windows PC does make it happen.
is this because of configuration of my mac book ore do more people have these problems?
There is no way of knowing that unless you write your mac specifications and AC version. I have been running AC since 2002 using Macs without problems on multiple projects. You can check the wiki for recommended configurations and models.