When building a runner system or cooling lines with beam elements or rebuilding localized elements, all these require selecting nodes, or so you think. While in the particular menu of what ever I am building, under "Selection option" the "Filter" is set to "Node", I have found that even though it shows "Node" you are still able to pick a random point in space where no node exists. If your model is in the right orientation it will appear correct but once the part is rotated it's obvious that the node you intended to select was not selected at all.
It would be nice that what ever the "Filter" is set to, that's all you should be able to select.