It works here. You can try to reset the configuration with the button in the preferences. Another possibility is to delete your config files or to move them in case you want to restore them.
If the problem persists, create a new topic, because it has nothing to do with the Cube, and add your full FreeCAD info.
Minor point on wording: This is not an addon it is buildin into the core system.
OS: macOS 10.16
Word size of FreeCAD: 64-bit
Version: 0.20.24612 (Git)
Build type: Release
Branch: master
Hash: f525904c1be10a0f55aa3502151c2c55e5054259
Python version: 3.9.2
Qt version: 5.12.9
Coin version: 4.0.0
OCC version: 7.5.1
Locale: C/Default (C)