Please let us know the following information to help you remove the watermark:
1. please login Smartpixel software with your account used to pay to confirm your account is VIP member account.
2. We'd like to know does the watermark appear every time you record a video? Or did it appear only the first time you run SmartPixel?
3. Have you tried to reinstall it?
4. Please open install directory. Go to 'Save' folder and delete opt3 file. Restart the program and try again.