Use Mesh Statistics to identify overlapping or intersecting elements. Once you have tried an automatic fix, if there are still problems, use Mesh Diagnostics to identify the remaining problems. Be sure to select Place results in diagnostic layer.
- Use the Mesh Diagnostics to find any problems. Click
() to toggle the diagnostic display on or off, and then Close once the diagnostics has finished. In the Overlapping Elements Diagnostic Display report, Intersections are displayed in red, and Overlaps elements are displayed in blue. 
Intersection
Overlaps
The node numbers that identify overlapping or intersecting elements are listed in the Overlapping Elements Diagnostic text report.
- Deselect all layers so only the Diagnostic Results layer is visible. Click on the Diagnostic Results layer to highlight it, then click Expand. The mesh around the highlighted layer is expanded by a specified level, in this case 1. This feature allows you to see what elements need to be fixed and the area around them.