When the computer submits the second grade paper, it shows that the file is missing.

This error means that your answer file is not saved correctly or in the specified location. Here are some possible solutions:

1. Check the file saving path: Make sure that your answer file has been saved in the folder or path specified by the examination system.

2. Check the file format and name: Make sure that your answer file is saved in the format specified by the examination system (for example. doc，。 docx，。 Txt and so on. ) and the file name conforms to the regulations.

3. Restart the examination system: If possible, try to restart the examination system, and then try to submit the answer again.

4. Contact the invigilator: If none of the above methods can solve the problem, I suggest you report the problem to the invigilator immediately, and they may be able to provide further help.