Maybe you have activated it using an old key code before. This is a registered version.
You have to go to the C: drive in My Computer and typing “%appdata%” (again, no quotes) into the search bar at the top.
When you are in the AppData folder, find the “ivscat.com” folder and detele it.
Then open 8K Player program, copy and paste the new Registration Code on the pop-up window.
Click “OK” to confirm, so you can use the app again.
Any other questions please feel free to contact at firstname.lastname@example.org.