I'm trying to download the game manual PDF for Scribblenauts Unlimited, and I'm having no luck. On the library page for the game, there is an "Additional Content" header with a link for "Manual".
This link is: https://store.steampowered.com/manual/218680/
However, it just redirects to the front page of the Steam store. This link seems to have been broken since 2013 based on these previous posts:

• https://gtm.steamproxy.vip/app/218680/discussions/0/648814738392243204/
  
• https://gtm.steamproxy.vip/app/218680/discussions/0/666828126928543206/

These posts mention the download link: http://support.wbgames.com/ics/support/DLRedirect.asp?fileID=606
This link has been dead for some time, and Internet Archive does not have copies of either the Steam link or the WB Games link that lead to a PDF download.

Steam customer support confirmed the Steam library link was broken and said I need to contact the developer. WB Games Support declined to help, stating the game was too old and no longer supported. I also contacted 5th Cell, which declined to help due to WB being the owner of the Scribblenauts series.