i've had that happen to me before. sometimes saving, closing greenfoot, and re-publishing works. if that doesnt work, i look through my code for errors like filename or nullpointer
Also, your project might be too big for Greenfoot's data base to save, I don't actually know, because I am new to Greenfoot, but I am guessing that because that is the case with Scratch, in Scratch, when your project is more than 10 MB, it can't upload and will just reload the upload bar over & over again.
@erdelf, ITS ALL YOUR FAULT (JK :+) It could be that your attempted upload has messed up the Greenfoot system so nobody can update or upload any scenarios. Actually, it could be that Greenfoot just happened to mess up while you were updating your scenario.. We are all getting the "Publish failed: Unrecognized response from the server. - 500" message.
When did I mentioned the 500 error code? It just starts again without giving me information
erdelf, exactly how big is your scenario?
Are you actually trying to send us a 700MB scenario? It probably shows that our server monitoring is lax that we haven't banned you yet! ;-)
I will look after it. It is only an update and I only added two pictures and a few lines of code
Sounds like you have something in there that's not meant to be there...
Ok. I looked after it. It was an archive which was from an old project. the file size was 667 MB