That error is from there being too much HTML submitted, more than a particular limit (as otherwise there's a performance issue). It's hard to see how much is getting submitted with the WYSIWYG editor, but you may wish to try to switch to the plain editor or shorten the text.
Ok, I think the best way is to release the big one is parts. But the file problem is not really a problem. I just created a .txt file with a little explanation, uploaded to my resource update and it is all ok now.