First, use the Chrome browser and open up the developer console (ctrl+shift+I or cmd+alt+I). Go to the Console tab, clear it, try t submit and see it fail, then look for any error messages. There will probably be one. If so, copy-paste it all.
It seems fairly likely that there is a specific spot in there that causes it to fail, rather than it depending on length. See if you can create a minimal test case. If you created the post by copy-pasting from an external program, it may be that that program inserted something hidden which is causing the problem. If you click the 'HTML' icon on the toolbar, it will show you the HTML source of your article, including any hidden things that might've hitched a ride on your clipboard.
Console tab says: POST http://lesswrong.com/api/submit 500 (INTERNAL SERVER ERROR)
Call me a neanderthal but Html looks greek to me.
When I sliced the entire text in small parts (all copied from Open Office) I manage to publish drafts, some with errors such as missing spaces.
When I re-copy from the drafts to another, bigger draft, then many spaces become missing, and part of the text is aligned to the right border, part isnt.
You could try making a small post first, then editing it and filling in the rest of the post?
I'm experiencing a problem trying to post a text to the topic session of LessWrong discussion.
When I write a small text (like this one) it works fine.
When I copy part of the text I intend to publish, and try submitting, still fine.
But if I copy most of it, or the entire thing, when I click submit the red sign saying "submitting" appears for a few seconds, then disappears, and nothing happens.
Does anyone know what happened or how to solve it?