I’m having the same or similar problem with my own site. I can post an entry without trouble, but once it’s been posted, I cannot update it. If I make any changes to it and click “update”, the screen goes white, and the post doesn’t update.
I’ve been dealing with this for months. My only work around is to make my changes, wait for an auto-save, click back to “posts”, re-open the post I wanted to edit, and then restore the latest auto-save. As you can image, not the most efficient way to do things.
Any ideas?