A student is having a strange issue; when she tries to upload a file in an assignment, the document becomes empty. This has happened to two different students. I don't understand why this happens or how to resolve the issue. The size of the files are 0MB, so there is no content whatsoever. The issue seems to occur in PDF-files, films and docx-files.
Edit: when she sends the files to my regular e-mail they work just fine. So there is nothing wrong with the files themselves.