Hello,
I am having the same error.
I have tried to update WordPress from version 4.2.2 to 4.3.1.
I have used the one click update but it stopped along the way and produced a server error. Which makes me believe that the issue comes from an incomplete update.
This is the error I get while trying to update:
Could not copy file.: wp-includes/class-wp-customize-nav-menus.php
Where you trying to do the same?
The website is still showing all the posts – the content is still in the databases – but it doesn’t show when I try to edit a post in the rich editor.
If anyone could help, much appreciated! Thanks!
Kind Regards
David
