I don't see the download button that you refer to.
I assume that this probably means my version of IE is out of date. If so, I doubt if I'll bother to upgrade at the moment, since I do have occasional access to a PC with more up-to-date software... and the content of the file is not critically important to me anyway.
The only reason I raised the issue on this forum was that my original Google search on the text of the error message seemed to me to suggest the problem might have something to do with the Reader itself.
Thanks for your help.