Delete any leftover data folders from C:\Program Files\Soundtoys and the paths noted in the architecture table above.
The error is almost always due to a leftover file, broken symlink, or permissions conflict in the C:\ProgramData\SoundToys directory. Deleting the conflicting item named “SoundToys 5” and re-running the installer as administrator resolves the issue in over 95% of cases. Full cleanup of previous installations is a reliable fallback.
Are you seeing this error during the or when trying to save a preset within a plugin?