Bug: error occurred when download course video

[Xanonymous-GitHub]

Describe the bug As title, a file system related error may occurred when trying to download course video.

To Reproduce

1. Go to a course iplus file page
2. choose a video and open it
3. click download
4. check the console

Expected behavior The video seems could still be downloaded, but we expect the error should not appear, too.

Screenshots