Okay but your issue is with some classifieds plugin it looks like.Activit
I can not say without more info here I have both plugins installs and running right here http://www.reeftalk.com/forums/forum.php
If your using older plugins they may not work. You need to uninstall any plugins then redo with the current ones in the software. As long as they are installed correctly as in the proper database info prefix are all filled out current things should run.
Look at your error. It is looking for your classifieds in your photopost database maybe?