Can't add new users or publish posts

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.

– re-uploading all files & folders – except the wp-content folder – from a fresh download of WordPress.

Site url?

@iamablogger – this thread is months old – please see this –

http://codex.wordpress.org/Forum_Welcome#Where_To_Post

And start a new thread here:

http://wordpress.org/support/forum/how-to-and-troubleshooting#postform