Basically, I have these area (part of a bigger map) containing many holes (e.g. lakes) I have thrown on the map some 1000 random points and I want now to count those that fall in that area. I already tried with "Data Management tools>Join by attributes" but I receive a geometry error. I also tried the "Vector>Count Points in a Polygon" but I still receive the geometry error. As I said before, I guess the issue is because the area I want to overlap with the random points contains holes. I would be really surprised to know that that one is the only reason why QGIS cannot count the points but I have to say I am a new to that software.