Many of you may find that while creating beams, sometimes the beams are unconnected. This can cause problems with 3D snapping and also cause the analytical model to become erratic and not behave sensibly.
The main problem is trying to find the offending beams. One easy fix is to use the course level of detail and structural usage. Below is the same framing layout in a course view. Notice that Revit Structure can distinguish between Primary members, secondary members and tertiary members. Also you can see that the beam with the very thin line has not auto detected the structural usage. This is due to it being unconnected. Quite difficult to spot!
If you use object styles and set the Other sub category to a garish colour such as Magenta then you can instantly see any offending beams.
I certainly found this useful on a few customer projects.