These three reasons are specific:

The file format of 1. is determined by the system risk department. As long as it's not uploading documents in wps format. They can be parsed normally when the system works. If the student uploads the wrong document format, even if it is successful, the detection will fail.

2. Check whether the number of words in the working document exceeds the version limit of the paper duplicate checking system, and characters exceeding 14000 are easy to appear. If the number of words is around 30 thousand, you can choose to take the test according to the article. If it is an English paper, the duplicate checking system also has the corresponding word count function, and one letter represents one character, so the system will count many more words. Before the paper detection, you can find out whether the school recognizes the results of the paper duplicate checking system.

3. Finally, the most important reason why you can't upload files when checking duplicates is that browsers don't support it, such as 360 browsers, but you can upload them again by changing browsers.