Hi, we had that problem with a large website and the pdf got invalid. it is most likley not episerver doing anything. In our case it was the load balancer running a new protocol for the web that was not supported by IE. It can also be configuration in IIS, https://technet.microsoft.com/en-us/library/bb742440.aspx, like mimetype.
Look in firebug for stange behavior when loading a pdf.
Our web users do sometimes experience that the PDF stops loading in IE 10-11. Any idea?
CMS version 8.10, NOT SSL, EI 10 and 11
It looks like the Adobe Plugin is loading, "Reading 584,4kb/614,0kb" then it stops. Sometimes needs to try 10 times before it works.
Example URL: http://www.holmen.com/globalassets/holmen-documents/skog/prislistor/prislista_ornskoldsvik_151001.pdf
The file i uploaded in Episerver "Media"
Is there some configuration in Episerver that can be done?