I just purchased codecanyon-2485867-wordpress-pro-event-calendar Used the plugin upload and got this message
Unpacking the package… Installing the plugin… The package could not be installed. No valid plugins were found. Plugin install failed.
When I unzip it I get bunch of folders, i am not sure what to upload.
Post your question on the item comments, or send a message to the author from his profile page.
The problem is most likely happening because there is a plugin .zip file inside of the .zip file you downloaded.