Well never mind me! I tried installing assetplacer 1.5 again (my clever brain missed the part in the description where it recommends what version to use). Somehow this time i enabled it with no issues and now i can use assetplacer! Yibeeee! Dont know what went wrong or how i fixed it im just happy it works :D
Edit: Oh my lawd it even works with Terrain3D, you mr are a gawd damn hero