Does the subject want to ask "Shaanxi professional and technical personnel continuing education learning platform, students log in, how come there is no QR code?" Platform problem, wrong login credentials.

1. Platform problem: There is a technical failure or operation problem in the education and learning platform, which prevents students from logging in normally.

2. Incorrect login credentials: the student entered the wrong user name or password, or forgot the login credentials, which made it impossible to log in successfully.