A problem with the previous site is that it was not getting used, and some of that was attributable to how a project posted on the site was different from what was posted on the forum - updating both was a bother and even if something was updated on the old site, if the project was older than the amount of projects on the first project page listing, the site update would largely go unnoticed.
If I am thinking about this right, the new project system seeks to make it so all site project topics are forum linked so that the site's content gets updated rather than stays dead. It also saves space because there are no longer two different areas which would get the same type of comments; the site projects' comment area is the forum topic. Also in the future when creating a topic for a project, the site will have to be used to create it. This more easily ensures that once a project is posted it will have the beginning requirements for being posted.
The error you are getting is because MG-Zero deleted the project he posted because when he created a project on the new site, it created a topic in Zelda WIP; he however already had a forum topic. It can be changed such that the topic the site refers to is one that is viable though, I will go forward with the edit to make that so. Edit: actually there seems to be an error where I cannot edit it, but I think I know how to fix this manually.