Perhaps you should read the bottom lines of the page? The one where it says
(Error dialog is fine) (Just press close and keep waiting!) if I remember correctly.
This would likely have been better posted in the WinterBreak thread since it has absolutely nothing to do with KOReader.
And really, considering the number of people who have caused themselves issues by watching YouTube videos instead of simply following the step by step instructions on the
WinterBreak page, I would not recommend following any YouTube videos unless you want to brick your Kindle.