With either of these issues:
- Reinstall Serum directly from the Splice app.
- Reinstall the Splice app as well; you can get the latest install here: https://splice.com/download
- Make sure there are no anti-virus apps blocking the installer, there are known issues with anti-virus software blocking the Serum preset files. Find out more about Antivirus interference here.
Lastly, there is a known bug with users who have Unicode characters in their OS user folder name (Any characters with special symbols like ñ, ø, î, é, 哦, etc.). Please try installing Serum to a location without any of these characters in the file path.
If you are having issues downloading your plugins through the Splice app you can manually download them here: https://splice.com/plugins/your-leases
Download and run the installer, restart your machine, open the Splice app, and run Serum.