The reason why students in the online examination of Tianjin University can't open it is that the computer system or browser version is incompatible. In general, students can't normally open online exams on their computers because the computer systems or browser versions are incompatible. The computer system needs to meet the requirements of Windows7 and above, and the browser version also needs to support HTML5 for normal use. You can view the computer system and browser version. If it meets the requirements, you can try to reinstall the online candidates or update the browser. If you still can't solve it, you can contact the customer service of the online exam students.