If you lost your installer, log into your FabFilter account. They keep all legacy versions, including Pro-Q 2.0.1, available for download.
: All filter types—not just low and high cuts—can utilize slopes up to 96 dB/octave , allowing for extremely steep and precise "brickwall" filtering. Fabfilter Pro-Q V 2.0.1 Windows AND OSX .rar
Version 2.0.1 specifically fixed several stability issues and improved VST3 compatibility on both Windows and OSX. If you lost your installer, log into your FabFilter account