To fix aspect ratios

3D mesh

1. Click (Mesh tab > Mesh Diagnostics panel > Aspect Ratio).
2. Use the Aspect Ratio Diagnostic to detect large aspect ratio elements.
3. Click (Mesh tab > Mesh Diagnostics panel > Show) to toggle the diagnostic display on or off.
4. Look for elements with aspect ratios outside the acceptable range. Use appropriate tools in Mesh tab > Mesh Edit panel.

   For example, depending on the specific problem, Global Merge, Merge Nodes, Move Nodes, or Remesh Area may help.