The easy one first -- from Post #21 -- the reason you're seeing the error about the PythonPlugins instance is that the Windows .NET framework is not installed. You can check whether it is or it isn't by looking in the Control Panel->Add/Remove Programs. The Video Converter app should install .NET for you if it's not there already. Did you by any chance stop that part of the installer or something? In either case, if you can reproduce this bug with a clean install, please let me know (via PM or in this thread) and we'll look into it ASAP.