An hour or two ago the last 12 games of the 1v1 SC table were deleted for unknown reasons. As a result, the games disappeared from the replay lists but the files were still there, which led to the fatal error that you guys reported. For an hour or two, nobody was able to upload any 1v1 SC games.
We are investigating the cause of this: we suspect that our host rolled back the database due to a possible crash on their end. We've added the last 12 games back exactly as they were, and you can now upload games. For all those who made a thread regarding manually adding games because of that error, you can now add those games yourself as normal. Sorry guys for the inconvenience.