We have a trainer who uploads marked assessments in pdf format to the students account, and when the student tries to download the pdf, it won't open, but says the file is corrupt. This happens with various students. But if the trainer sends the pdf to the student via email, it is fine. 

Something is going on either when she converts to a pdf and uploads to Totara or when the student downloads it. But the fact that it happens with multiple students leads me to think the bug is in the trainers process. 

So when she uploads the pdf to the system, something is going wrong. 

No other trainers/users have this issue, that we are aware of.

Has anyone experienced this and found a solution?

Many thanks