It is now known ...
I just noticed an error where anonymous is presented with thatWe were returning the wrong error incorrectlymessage.
Were you logged on?We have a special case where we totally disallow suggested edits from child meta sites (like this one) but the check was deferred a bit.
What post wereI just fixed this, so you trying to edit?should not see this message anymore unless the queue is really full (it fits 20) and has never filled up for the photo site.