Happens in any kind of edit on some Credits pages. The Red Bar of Death appears almost immediately. The first game that gave me the error was (naturally) Age of Barbarian. Editing any part of its Game Credits page gives back an error message, and saves no changes.
Doing any edits on the Red Dead Redemption Credits page sends back the Red Bar of Death, as well. It always had problems (probably because it's a huge page), but you could do annoyingly small edits and force things through before the code merge. Now, nothing gets through.