First of all, there may not be enough hours and kilometers. According to the regulations, subject 2 training is not less than 26 hours, and the exam needs to be practiced for not less than 70 kilometers. Without enough hours and kilometers, you can't pass the examination and approval. Secondly, it may be that the photos are unqualified. When punching in for subject 2, the system will compare photos. The photo is unqualified and the class is invalid. This may be because the photos are of poor quality or do not match the identity information. Another possibility is that the system data is wrong. The failure of the subject 2 exam may also be caused by system data errors, such as class record errors or other technical problems.