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After I had upgraded to 3491, I had found several glitches, one of which was this one. I had finally completely uninstalled Intel XDK, using a professional grade uninstall app, and then reinstalled it. When uninstalling it, it doesn't touch your project folders. Select to uninstall everything. After you reinstall it, you have to load you projects. I have found that it works a LOT and I mean a LOT better after I had completely uninstalled and then installed it from scratch.