Please retry electronically filing your stimulus registration later today.  This issue should be fixed.  

Make sure that you are using this link for your Stimulus Registration.  Here is where you can find where to file your Stimulus Registration on this link:

I tried the link you provided but still can not download the paperwork to mail for Stimulus Registration

Make sure that you are using this link for your Stimulus Registration.  When you are on this webpage, scroll toward the bottom and select, If you don't need to file your taxes this year.  Please try electronically filing this registration again.