A guy from WordPress Team are banned Knews from the WordPress.org repository yesterday 25/09/2013.
He think our automated update system from Knews to Knews Pro (after serial number insertion) violates the guidelines.
From 26/09/2013 Knews was turned up in WordPress.org, but we forced to remove the easy upgrade to Pro.
From now, if you are using Knews Free and want to upgrade to Pro, you will need to download from our webservers and upload through FTP only the first time.
Once Knews Pro is installed, you can upgrade as usual, with one click in the Plugins admin page.
The Knews Team