Creo Direct > Designing in the Creo Direct Environment > Working in Part Mode > Working with 2D Geometry > About Geometry Checking
  
About Geometry Checking
A geometry check warns you of potential geometry problems with the model when creating it. You can view and investigate the geometry check problems using the Message Log dialog box. Problems with geometry can arise due to one or more reasons:
Bad surfaces, two-sided edges, or wireframe curves
Edges with poor tessellation
Short one-sided edges
Small and narrow surfaces
Vertices without coincident edges or surfaces
A round with a radius that is larger than one of the adjacent surfaces
Overlapping geometry