High edge density or "stray" lines on the top face can confuse the plugin. Use an extension like CleanUp³ or Curvizard to simplify the edges of your face before rounding.
If you try to round a 10-inch wide box with a 6-inch radius fillet, the math demands a curve that physically overlaps itself. The plugin attempts to force it, often resulting in the top face collapsing or cracking open because there isn't enough physical space for the curve to exist. sketchup round corner crack top
[Attach image of the crack]
Seeing "cracks" or gaps on the top face of your SketchUp model after using a rounding tool is a common headache. It usually happens when the geometry gets too complex for the plugin to calculate cleanly, or when SketchUp's internal "tiny face" limit is triggered. Common Causes of "Cracks" High edge density or "stray" lines on the
: Rounding holes or non-orthogonal intersections can sometimes confuse the algorithm, causing it to skip the top face or leave "bad geometry" at the corners. SketchUp Community How to Fix the "Cracked Top" Issue The "Scale Up" Method (Best Fix) Turn your object into a Make a copy and scale it up by 10x or 100x RoundCorner The plugin attempts to force it, often resulting
Use (by ThomThom). Ensure your object is a solid group (no stray edges, no holes). A single internal line is the #1 cause of the crack top.