New users or people who missed greenlight can't use the /greenlight command. The related greenlight ingame guis still exist too.

The only way for users to unlock the green light is to put steamGreenLightGui.clickForwa
rd(); in the console or download the gui editor and find the greenlight gui.
I was wondering if this problem could be fixed somehow, like removing the need to do these or something. Would be cool if badspot does something, I PMed him a while ago.