i re-installed all the mod tools when i experienced this problem and it did not fix it. Now i spent the last week searching for someone having the same problem but i have not found a thing. if anybody could help it would be appreciated 

So you mean this: http://gyazo.com/a5e9c7f53c4a5140cfaa27b603633315

This is for the brushes. Select a brush and then click the Simple Terrain Patch and choose the terrain density.

For more terrain you can open a tool with "Y"

Select a terrain click "V" click then in this tool PaintHeight. With ALT and Left Mouse you go up. With ALT and Right Mouse you go down.

Hope it helps

thanks for the response , I am talking about the advance terrain editor. The small window that's suppose to open does not open. Lol so I can't blend textures like I use to.

thanks for the response , I am talking about the advance terrain editor. The small window that's suppose to open does not open. Lol so I can't blend textures like I use to.

You mean the window when you click "G"?

Since this isn't closed I'm assuming you'll still take an answer -

Move your ask bar to the side, it's either under the right bottle or the left bottom of your screen. Same thing happened to me :p