The lecture delivery and content are very good. However, since it is a lecture from about 3 years ago, there are many bugs due to the version mismatch. As a beginner, it is not easy to match the version of the library, so it is difficult to proceed with the lecture. It would be difficult to re-record the lecture, but since this lecture is sold for a fee, it is necessary to at least mention the method of resolving the version conflict for beginners.