@Anonymous - That's interesting. The error is misleading, at best, and my guess is that it is kind of a "throw up our hands/default error" when we don't know what else to report.
In my opinion, this illustrates the hazards of working with imported (presumably SVG) sketches, and scaling a sketch. Imported geometry does not have constraints that hold it together, so under a scale operation, you can get gaps or other anomalies in the resulting geometry. Also, this sketch has about 5000 entities in it, which makes working with it in sketch really challenging. So, I'll go back to my original recommendation: Just scale the body. If you need sketch lines for doing CAM toolpath operations, I'd just create a second sketch on the resulting top face of the Extrude.
But, I can offer a bit more insight into what I found looking at this sketch after the scale. Using a version of the "divide and conquer" technique here: find-break-in-sketch-geometry I was able to find the area that has the problem:

Then, further refining this, to this small area:

zooming in close, you can see some problem sketch geometry:

If I deleted all those extra curves, I can then extrude OK:

However, I did find another problem with your scaled sketch - the main internal profile of the Marlin is no longer recognized after the scale:

using the same divide and conquer technique, I found another problem:

I did the same basic thing to repair the sketch in this area, and then can extrude the entire shape OK:

I've attached this repaired version to this post.
I guess my recommendations would be:
- Be careful, or avoid if you can. using imported SVG or DXF data - there can be a lot of curves, which makes Fusion's sketcher crazy, and if scaled, can result in these types of problems. Systems which create SVGs are notoriously imprecise, and generate a LOT of curves. Fine for doing 2D art, but not so great for a parametric CAD system. If, for instance, you ever want to try to fillet the termination edges of this extrude, I would not predict success.
- I still would prefer to scale the body, not the sketch
Jeff Strater
Engineering Director