it would be interesting to see if the errors log shows anything. This looks like an unusual error. I quickly tried to download the file through a lab MWG 6.9 and it worked pretty fine. I think this needs some more investigation.
Maybe someone else can try to download the file, so we can see if this issue is specific to your environment.
Yep - comes through as expected here.
I suggest talking to support as these internal errors, ca come through multiple things, e.g. url filter pattern broken, library not initialized, etc....