Hi, I’m new to the forum. Can you help me? I have an imported scene to make a virtual tour. I’ve added player start to preview in first person but I don’t have gravity. Do you know how to apply gravity to player start? I also want to change the values of the player start capsule because for the preview to be at the height of a person’s head the player start capsule has to be higher. I’ve tried to change this last thing in the Blueprint in the capsule node. Apparently when I change the value the capsule gets higher but then in the preview it goes back to this as before. In short, I don’t have gravity in the scene for the player start to walk on the base and without that it stays in the air and I can’t change the height value of the capsule either.
You can navigate to the world settings window and search for “global gravity”. If that’s already set to the desired value, try opening up your character blueprint, click on the movement component and search for “gravity scale” on the details panel. Play with that value and see what happens.
You can click on the capsule component which should be listed in the same window with the character movement component (on the components window) and search for “capsule half height” on the details window that pops up on the right side when you click on that. You can adjust it’s height, location, anything to a desired value.
That’s because it’s not a permanent adjustment. Blueprints get triggered on runtime, and can even not be triggered if you set it so. You can use them to handle the capsule component height dynamically while playing, like when the player crouches etc. What you’ll see on the viewport depends on what you set the settings from the editor.
Hope these help! 
Oh I think I know what’s going on. I think you don’t have a game mode or a player pawn in the first place. Let me know if that’s the case 
I’ve already tried what you’ve answered but it doesn’t work
I think it will be the last thing you mention. This scene is started from the architecture example, which only showed me the base plan, a player start and a camera at the beginning. Then I imported the scene from a 3D software.
How do you configure a game mode or a player pawn? Thank you
In the player class settings/defaults for “enabled gravity” and “simulate physics” you’ll want these checks on, or they can be called and set on begin play, youll also want to ensure collisions are set up appropriately on both the character and world meshes, or any collision components like a capsule on the players character class. To dynamically change the capsul, you can call “get local bounds” on its child mesh, then plug that into a "set extent " node for the capsul component
That checks out then 
Here’s a video: https://m.youtube.com/watch?v=JP3LnXDQet8
It works!! Thank you very much. I followed the instructions in the video and everything is perfect. Thanks!! I suppose that this configuration can be copied to another scene to use it without starting from scratch.