I had the same issue. You probably didn't apply the promo code to upgrade your account, even though the redemption link is supposed to activate it with the code.

I also have to same issue with you. How do I remove the watermark after buying the deal on appsumo.com still the water mark removal is not valid.

Watermark issue is really a waste of time.
If offer says "No InVideo Branding or watermark", should be like that, Period!
Please I'm waiting for your help.