Ok guys so. This happened to me a couple times and it was a total disaster.
Guy takes along with his army, a villager, cuts a tree, puts a palisade, deletes it. Whole army gets in.

Is this a bug? Is this lame? I don't know.

But I did try this by myself, and it never worked. I don't know why. One day I felt like laming a bit, and I cut the tree, but I was unable to build a palisade on top . Why is this?

Same as placing gather point on boars. How is that done?

Thanks for your reading and awesome comprehension!

Ahoooyyyy

I know you can place a foundation on a tree in order to remove the tree (if it has been cut down). If you can't then perhaps it is the type of tree or the type of building.

They were able to do it because it was one single tree, not part of a bunch. Therefor you are able to use the pal wall trick.

Also in order to avoid people from doing it to you. wall behind the tree. Or cut it and wall yourself.

thanks i will try that.