There are many reasons, one may be that there are loopholes in the software, and the other may be that the software is incompatible with the computer system. For example, this kind of software requires that the version of word, ppt and excel is 20 10, and other versions are not available. In this case, you can only reinstall a new software.

The scoring system is for reference only. The key is to practice. As long as you follow the steps, you are sure to pass the exam.