MP3 Audio File
One of the reasons that empty assignments are uploaded is because the .pdf file (the document that was edited by the student) was not downloaded to the laptop before the student started typing the answers. To prevent this scenario, the file must be downloaded and edited on the laptop.
Click the three vertical dots in the upper right hand corner of a Chrome window to reveal the browser's menu options.
Click "Settings".
Scroll down the Settings page to the "Privacy and Security" section.
Click on "Site Settings"
Scroll down to the "Additional Content Settings" and click the down arrow to expand that section, if required.
Click once on "PDF Documents."
Slide the toggle button to the right to turn on "Download PDF files instead of automatically opening them in Chrome".
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Click the three horizontal dots in the upper right hand corner of an Edge window to reveal the browser's menu options.
Click "Settings".
Type 'pdf' in the Search settings box
Scroll down until you see "PDF Documents."
Click once on "PDF Documents." and make certain the ' setting is on (i.e., the button is to the right.) means
Slide the toggle button for 'Always download PDF files' to the right to download PDF files to the computer rather than automatically opening them in the browser.
After updating the browser settings as shown above, PDF downloads will be downloaded to the laptop going forward. Your child will edit the document on the laptop, save it, and upload it from the laptop into the assignment for submission and that will eliminate the risk of submitting blank pdf files.