It looks like you have tried multiple invalid keys before making a genuine purchase.
This leads to such errors. To resolve, follow the steps:
Please go to C: drive in My computer and enable viewing hidden files and folders:
https://support.microsoft.com/
Open Program Data/Movavi Video Editor Plus 2020 folder and remove all files in that folder.
Then launch Video Editor Plus and try activating with the given key.
https://support.microsoft.com/
Open Program Data/Movavi Video Editor Plus 2020 folder and remove all files in that folder.
Then launch Video Editor Plus and try activating with the given key.
Please let us know the result.
Thank you.