The message is displayed when the save operation fails on the new message. I wouldn't expect the save operation to fail unless there is something wrong with your connection to the database. Did you run the upgrade script?

I ran the upgrade script, http://site.com/upgrade.php

It would seem that wire posts and other information goes to the river just not mine (the admin). If I do something that should post on the river it gives me a fatal error message "Fatal error: Exception thrown without a stack frame in Unknown on line 0"

The issue seems to also now affect my plugins, if I add new settings and save them they are blank afterwards. If its no longer writing to the DB how can I fix this?

Okay, so I've gone into my database and repaired all the tables and still having the same problems. I'm at a complete loss as to what I'm going to do to fix the issue.

no suggestions from anyone?

would I just be better off to backup the databases, delete my elgg installation and start again?

I have no idea about this situation, do I just need to delete and start again? Any help on this matter would be greatly appreciated.