I spent years watching people blame the file when the printer never got a first layer.

A "print-ready" STL is a mesh that already has the right orientation, wall thickness, and clearance. It is not a magic bed. If your skirt doesn't stick, the STL is not the problem.

Quick check before you reprint

• Skirt doesn't stick → wash the bed, raise nozzle temp 5°, slow first layer to 20 mm/s

• Corners lift → drop cooling for the first 3 layers, add a brim

• Layer shift → belts and acceleration, not the model

• Stringing → dry the filament

If the mesh itself is junk — holes, 0.4 mm walls, floating parts — no slicer setting saves it. That's the difference between a random download and a file that was actually printed.

If your printer is the thing that's broken, that's a live session, not another STL.