This is something I've been dealing with for a couple days now. I can't save any posts that are maybe 4 or 5 thousand words in length. And yet, I can easily post a very quick 'test message' of just a few keystrokes. Something fishy in Denmark!
I didn't find anything worthy of note in my error log...just a couple things that had to do with a theme that was causing a problem.
NOW I'm beginning to wonder if my current trouble might be due to posts that are "too long"?
Found advice about the "wp_settings.php" file. This is supposed to help:
if ( !defined('WP_MEMORY_LIMIT') )
I see the file in my FTP, but how do I open files like these? Each time I've tried, I get a nag screen about PhotoParade which I don't have. Could I just download the .php file to my own drive and view it from there, fix it, then upload it back to the other server? I never use PHP files so I'm not sure!