MTB is a variation of the MT2 plugin geared towards the bass. The cut frequencies for the different filters are lowered to match the bass frequencies better. As such, MTB spills less in high frequencies than MT2. Not that MT2 cannot be used for the bass if that’s the sound you are looking for!
This plugin requires the universal runtime on Windows, which is automatically deployed with Windows update (see this discussion on the JUCE forum). If you don’t have it installed, please check Microsoft website.