The Trapped Beam diagnostic is used to locate beam elements that are overlapping, as indicated by the position of their centroids.
The diagnostic looks for beam element centroids that are contained (or "trapped") inside other beam elements, and highlights them in red.
To access this diagnostic, click 
().
Click Show to display a graphical representation of the results and open the Diagnostic Navigator. The Diagnostic Navigator appears on the ribbon on the far right side. Click the arrows to move to the next element with a potential problem.