https://www.shapeways.com/model/209855/lazopiece.html?gid=ug2 7073 The website accepted my upload, but when I tried to order it, now it says "unprintable." What might be the problem? It's a simple design and looks easy to print. Thanks for any clue.
It may be the height of the piece, try rotating the piece like 25 degrees on the x axis and re-uploading. This will make the height go up enough to be in the printable range.
It might sound obvious, but did you log in first before trying to order? Other than that, it's either a glitch, someone's reported its or something completely different. Maybe try uploading again as a new model, or contacting customer services - link at top of page above the upload button.