Disaster averted. You can now download the new and improved GrutBrushes plugin from your account page. With yesterday’s release of a new version of Photoshop CC (16.1) Adobe broke a ton of plugins including the GrutBrushes Digital Artist’s Toolset Panel when they turned off Node.js by default.
Today, less than 24 hours later you can download a new compatible version of the plugin (thanks to hard work of Zetta and their adobe scripting wizardry) If you have previously downloaded the plugin it is ready for you on your account page, if you haven’t downloaded the plugin you can get for free here: GrutBrushes Digital Artist’s Toolset Panel for Photoshop CC (2014/15)
You will have to uninstall the previous version before installing this one. If you haven’t updated Photoshop to the latest version (Nov 30th) you won’t have to do anything and your GrutBrushes plugin should still be working fine.