Can someone confirm this bug with Hammer(version 4.1 build 6048)? 1. Make a few brushes (or displacements) 2. Group them all together (Ctrl-G) 3. Browse for a new texture 4. Click "Apply Current Texture" icon 5. Press Ctrl-Z to try to undo the texture I would expect the first time I press Ctrl-Z to undo the texture, but sometimes it requires me to press it two times, sometimes 5 or more, and sometimes it won't even undo it at all. Also, when it finally does undo the texture, it un-groups everything. It may even select a random nearby brush while stepping backwards through the undo's. Strange behavior. The work-around is to just use the Face Edit Sheet to apply textures to groups, or to just not use groups.