Back in December FabFilter updated Pro-MB and Pro-Q 2, in which they introduced Retina support and new features in the Pro-MB.  However they have found a couple of issues that they wanted to fix as soon as possible. These latest versions contain these various bug fixes along with small improvements.

What Is New In FabFilter Pro-MB1.11 & Pro-Q 2.03?

• Fixed a bug that caused knobs and sliders to respond incorrectly to subtle mouse movements while dragging on OS X and on High DPI displays on Windows.
• Pro-MB: Renamed the existing interface size options to Medium and Extra Large, and added a new intermediate Large option that will fit comfortably on 1920x1080 monitors on OS X.
• Pro-MB: Fixed a bug when deleting a muted band in Dynamic Phase mode: the mute effect would remain audible after deleting the band.
• Pro-MB: Fixed display behavior when zoomed in horizontally: display curves and dragging would not work correctly for bands docked at the left or right edges of the frequency scale.
• Pro-MB: Fixed sidechain filtering control behaviour when zoomed in horizontally in the display.
• Pro-MB: Fixed possibly incorrect gain change reporting for bands that use compression in combination with a Stereo Link setting below 100%.
• Pro-Q 2: Fixed a bug in the VST 2 plug-in (introduced in Pro-Q 2.02) that caused the Auto Gain setting to always be set to Off when loading sessions saved with Pro-Q 2.01.