Hi again Falcon
I downloaded the script and placed all the files in the folders that were described in the installation instructions, and everything worked fine for me. So there is nothing wrong with the script.
From looking back over your old posts, it seems that you may have missed the MAYA_PLUG_IN_PATH variable from your Maya.env file. Make sure this points to the folder in which you placed the plug-in.
Also, make sure you are using the correct version of the .mll file (There is a .mll file compiled for each version of Maya) and you will need to point your MAYA_PLUG_IN_PATH to the correct one for your version of Maya.
As a test I created a folder on the root of my C:\ drive called MyTestFolder and placed all of the files in sub folders in there (See the attached inamge). Then I created a Maya.env file in the prefs folder and added these lines to it:
MAYA_SCRIPT_PATH=C:\MyTestFolder\scripts\
MAYA_PLUG_IN_PATH=C:\MyTestFolder\plug-ins\2014-x64\
XBMLANGPATH=C:\MyTestFolder\icons\
Then I restarted Maya and ran the command
SHAPESBrushUI
And the tool popped up with no errors.
So in summary, it looks to me like you are missing the MAYA_PLUG_IN_PATH variable or you may be trying to load the wrong version of the mll file.
Finally if this still isn't working, can you copy the contents of your script window after starting Maya and trying to run the tool and paste it up here.
Thanks
Mike