What has happened to my SketchUp model? I have spent a month slowly working on a SketchUp model, saving regularly, and saving under a new file name after any major updates, so I have file01.skp, file02.skp, etc. and each exported to MeshLab as a 3DS, and exported to Netfabb as an STL. This worked well. Today, I began work on a seperate project, to be uploaded as an X3D file, with colour. That didn't work well at all, and I abandoned it. Now I find that my previous STL files, which had been perfectly fine up to now, will not load properly in Netfabb either. They appear corrupted, and cannot be selected for repairing or exporting. Whatever I did with the X3D file, seems to have corrupted everything else too. I will have lost over a month's work if I cannot rescue this. Why won't my STL files open in Netfabb properly, having been perfect up to now? Is it to do with file size, or scaling, or something else? Has anyone else had this trouble, and can anyone advise? any thanks.