I accidentally removed my brush palette while I was adjusting my interface. The Palette icon returned after I restarted Zbrush, but I can’t open it any more. It’s a dimmer grey and it won’t let me select brushes. Init Zbrush didn’t restore it, and neither did re-installing. If anyone knows to to restore the palette please let me know.
The Brush palette is disabled unless you have a mesh in Edit mode. Load up the DefaultSphere project from Lightbox and see if the brushes become available.