3D FlipBook - Pro Plugin purchased but not able to download to plugins

Hi there,

I have purchased the pro version, removed the free one, trying to upload the pro version from files but I'm getting the following reply. "No valid plugin" but this is the file that was downloaded from the emailer received, money has been deducted, but the file does not work. Please assist.

Unpacking the package… Installing the plugin… The package could not be installed. No valid plugins were found. Plugin installation failed. Return to Plugin Installer