Hello, I was helping another instructor import content from my course to theirs, that worked without any trouble, but now when I click on any of my PDfs in any of my current and previous classes I either get a "Failed to  Fetch" error or just a loading wheel which spins and spins.  The PDFs are downloadable by clicking on the three dots at the far right but the downloaded PDF has 10 extra blank pages.  I tried to replace the offending PDFs with new renamed ones but the same thing happens. I have never encountered this before, so my question is, what is happening here and how should I correct it?