How can i paint trees on a terrain?

I have downloaded a tree model off the internet and made a prefab in unity and added it to the paint tree section but i am unable to paint tree. I am using the latest version of unity.

 

"latest version of unity" that doesnt give much, what exact version are you using? How were you "painting" trees, using terrain tool? using polybrush? using a 3rd party tool? By hand?

 

im sorry for the lack of information, i was using the terrain tool with a tree prefab i downloaded of the internet. Im using unity 2018.3. I do receive a warning in the console saying the prefab doesn't have a valid mesh renderer even tho i have added the Mesh Renderer component.

thank you for your time.