ditto, MB, but it's not happening for me
How weird - you received a different error from the one that I'd gotten before I'd fixed the double-quote problem in Post.php. I successfully uploaded attached a JPEG, but you tried a GIF. So, let's see if I can attach a GIF...
Nope, I can't. :- So, let's try another JPEG...
How bizarre, I'm getting the same error for a JPEG, too - even though I was obviously able to do it the first time.
Well, I'll definitely check out the line in the Post.php script that's referenced in the new error, and we'll move on from there.