The player wont walk up the stairs / How I make my player walk up the stairs properly in terrain /LOD group problem

I have added a mesh collider so the player wont got through the stairs . Now I have another problem the player wont walk up the stairs . I have to jump up the stair and when I get up the stairs I can’t walk all the way around the tree house . The house also has LOD group attach to the house .

The player is stuck .I also have to jump in other places . So is their something I need to change here ? I have some pics here :

add an invisible mesh collider that looks like the picture attach here75439-pathway-stairs.jpg in the stairs. you can walk properly now because its straight and not crooked. as for the other parts of the house. I recommend making your own mesh collider and turn of the house’s mesh collider cause as you may know by now you can’t really walk on a crooked mesh like that unlike the straight and parallel once .