You need the latest version of LibFredo with SketchUp 2013...
Fredo has recently updated his Lib and several of his tools to ensure their compatibility with v2013.
Visit our PluginStore to get the latest rbz files and install them...
Or get the SketchUcation Plugin Store tool and install it from its rbz... then you can AutoInstall them [and hundreds of other plugins] directly from within SketchUp 2013 itself...
You'll need to restart SketchUp after AutoInstalling the Lib, but the other tools should AutoInstall dynamically.
The toolset also includes the Plugins and Extensions Managers...