I'm stumbling over a lot of unexpected 500 errors recently when opening submissions from my news feed. Upon opening the details of a submission it just says "500 an unexpected error occurred".
When I opened the user's page and looked into their gallery, the picture shown to me on my newsfeed wasn't anywhere to find in their gallery page, probably causing the 500 error to show up. Or maybe the picture still is in the user's profile, just not public, since it keeps showing up despite reloading the news page. I can even interact with it (promoting, faving) without error and reloading keeps the interactions intact. But the submission page always results in a 500 error.
During news feed aggregation there should be a check if the current logged in user is able to view the pic's submission page before it is presented in the news feed, as this type of behavior is hell of a lot confusing.
Customer support service by UserEcho