I noticed that earlier and when I made a post it didn't look like it went so I opened another tab and checked and it was there. Just a few glitches to still work out.
Yes, it seems you are right. My post came also up twice and I saw this error above!
I see why people messages are coming up more than once. It comes up with an error at the top of the screen and you think it has not been posted and you click submit again. But it has posted it.