: 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
Undo the fillet. Delete the internal guide line. Soften the top face edges. Re-apply Round Corner. Result: Perfect, crack-free top. sketchup round corner crack top
If the above solutions do not resolve the issue, the following workarounds can be tried: sketchup round corner crack top
SketchUp gets confused about inside vs. outside faces. sketchup round corner crack top