Can't see the point, streamline and line in Post

Atit

My model is compose of three circular pipes. Actually it is just the flow in pipe. However I would like to model the momentum source at the middle length of the pipe. Then I create the pipe as three portions, and specify the middle pipe as the subdomain for momentum source. It converge properly. I create the plane in Post to see the pressure along the axis of the pipe. It seems correct. However when I create the point using crosshair as the symbol I can't see that point no matter how big the point is. When I change the symbol to others, e.g. ball, I can see that point. Then I create the streamline generating from that point I can't see the streamline. I tried to create the line along the pipe axis too, and I can't see that line. Do anyone have an idea about this? Thank you very much.

Atit