The "version root folder" is typically located in one of two places:
try resetting the Temp folder to its original location, which would be C:\Users\_your_user_name_\AppData\Local\Temp. Gearspace
If you are updating, manually delete existing Soundtoys folders from the locations listed above, empty your trash, and restart your computer before attempting a fresh installation.
Soundtoys V5 Preset location, presets not saving and hardlinks