Have you tried:
– deactivating all plugins to see if this resolves the problem. If this works, re-activate the plugins one by one until you find the problematic plugin(s).
– switching to the Twenty Eleven theme to rule out any theme-specific problems.
– resetting the plugins folder by FTP or PhpMyAdmin. Sometimes, an apparently inactive plugin can still cause problems.
– resetting your custom permalinks back to the default setting. If this works, then review Using_Permalinks before setting a custom permalink structure back up again.
Hi i am having the same problem on my site http://allaboutedu.com/
i am not able to create new Pages. i have about 5000 pages – could that be a problem. i am currently using themezee or could that be the problem. i have deactivated all my plugins and tried that already its not working.
i have also installed plugins revision control and WP-Optimise, but its still not solving the problem.
please help.