Trouble with an external links - my % changes to a ? ... why

Hello all,

I am having an issue when trying to redirect to an external website at the end of a successful quiz.  In the "Pass Result" slide, I am placing a hyperlink in the message free text area.  The link is rather lengthy and includes a couple % at the end.  When I publish the quiz and click the link the address is identical except that the two % have been changed to ?

If I manually change them in the url back to % they work fine.

I've double checked the URL in the original file and published a couple of times with the same result.

Any thoughts?

Thanks so much,

Craig