Player keeps falling through the floor

i am building a ark map and when i try to use the play command or the play from here it starts playing but it keeps on falling all the time, all the collisions of my landscape are set to ground and to play from player start. i have even moved the player start higher than the floor so it does not let me spawn under but it was of no use because it keeps on falling and then eventualy dies. please can anyone help because i cant just simply abandon/start another world because a lot of time has been put in it.

If you select the static mesh, what is the collision type set to? Try setting it to BlockAll

it is set to ground