Can't delete shape vertices

[migueld83371718]

Hi, I was working with some shapes editing and deleting vertices, but sudently, I'm not able to delete selected vertices. I select a vertex with subselection tool, and I press delete key, but the vertices are not being deleted. Anyone know why this can be happening? 

[kglad]

that can happen if your trying to edit a symbol (instead of a shape).

ie, try double clicking whatever object your trying to edit.