What we tested

FilePrusaSlicer saidActual problemResult
40 × 20 × 12 mm block saved in metersNo layers were detected. …Clean solid at 1/1000 scaleNot sliced
40 × 20 mm surface, no thicknessNo layers were detected. …Open sheet, height 0Not sliced
40 × 20 × 0.2 mm plateNo warningClosed solid, one layer thickSliced as one layer
PrusaSlicer 2.9.6, macOS, command line: --info gives the object-list statistics; slices used the defaults with a 0.4 mm nozzle, 0.2 mm layers, supports off. "Same filament" compares G-code from the original and from FixSTL's repair. Nothing was printed.

What is going on

The message comes from the slicing step (source). In the app, PrusaSlicer offers to convert a model that looks like it was saved in inches or meters when you open it (source); declining leads here.

FixSTL reported the meter-scale block as a clean solid and the sheet as 16 open edges with a height of 0.

What was actually wrong

How to fix it

  1. Check the size in the object panel. If it is tiny, scale by 1000 (meters) or 25.4 (inches).
  2. If the size is right, check the file in FixSTL: a height of 0 means a surface with no thickness.
  3. Give the surface thickness in your modelling program and export again.

Source: Seen in our tests · PrusaSlicer 2.9.6 on macOS