Serum is asking for a Serial number (Splice RTO)

Try signing out and back in to the Splice app.   

When using Splice RTO, you should not be asked for a product key for Serum. Since you are, this means one of a few possibilities: 

• you had previously installed an old copy Serum on the computer and it is (now) running.
• Splice has not unlocked Serum on your computer (very likely if you're on a new computer")
• Splice has revoked a license from a failed payment (likely if it worked before)

What to do to unlock Serum rented from Splice:

• Try signing out and back in to the Splice client app (If you need to download the Splice app, you can do so here: splice.com/download)
• If that does not resolve it, verify your payment info is up to date on their website.
• Check Splice support and/or contact them for help.

Keep in mind you need to be connected to Splice app online at least once every 3 days but once you have paid off Serum, this is no longer needed.