I'm sure this has been suggested before, but I didn't find an existing thread.
One of the biggest problems with mod sites is that they gradually fill up with mods that don't work anymore. Games get new updates, and mod-makers have moved on to other projects and don't update their mods to work with the new version. That's fine, that's how things go.
But the only way a mod-user can tell if a mod still works is to try to comb through a mod's comment section to see if people are complaining about it, or they have to download it and find out on their own.
We have an "Endorse" button to mark mods that we think are good. How about a "Broken" button so we can mark that a mod doesn't work anymore? Once its broken-to-downloads ratio reaches a certain point, the site could flag it as "possibly broken", and then "probably broken" if it's even higher. And the Broken rating could automatically clear itself if the mod-maker uploads a new version.