Falling through the terrain to the floor

Hello I need help as for some reason now . I am falling through the terrain all the time . I have tried moving my spawn in different places also when i create a terrain the pull down menu says cube world and primary. any help would be great thanks Tezza

I just made a new project with a default cube world terrain and there is no problem for me. I suggest you test the same way until you can find what is causing your problem. Have you made sure the spawn point is completely above the surface of your terrain (you will see it start to shade in as you lower it into the terrain - press v to turn on volumes)?