My Toolbox / Hoe Wizard worked and let me create holes before the installation of the 2021 beta, after this install my 2020 data folder vanished!
During installation, there is option to install Toolbox.
Make sure that and SW is install in different folders for each version.
I think you'll need to uninstall 2021 and repair/reinstall 2020.
If you have a second installation on another computer the easiest way is to copy the SOLIDWORKS Data folder from it back over into your folder (I assume it has been overwritten with 2021 files). If not, than you got to run the installer and re-install toolbox.
Retrieving data ...