We had an image file name that contained a space, your resource extractor was replacing it with %20 as if it were a url. Since the reference to it no longer worked, we renamed the file to use an "_" instead of the space. The generated file under the /Bin/Output/Resources tree did not change it's name. I deleted the entire /Bin folder, the old filename still got generated. You can clean, rebuild, restart Visual Studio, even reboot, the old filenames in the output tree are still there and the new ones are not. Adding a file to the source directory appears to make it all update properly.