Somehow forum's got associated to wrong taxonomy vocabulary. Need help I am using Advanced Forum 2.6 and I noticed that some of the views were set to pull the wrong vocabulary instead of the forum vocabulary. I set them all to pull the correct vocabulary but when I go to /forum the page title is still for the incorrect vocabulary and any change I make at admin/structure/forum also affects the terms in the previously connected vocabulary. It seems that the database is confused and I'm not sure how to reset things. 

I am also getting a pair of the following errors for every term:


  Notice: Undefined property: stdClass::$num_topics in
  mothership_preprocess_forum_list() (line 49 of
  /Users/seankennedy/Documents/_IWS/drupal/sites/all/themes/mothership/mothership/functions/forum.php).
  
  Notice: Undefined property: stdClass::$num_topics in
  mothership_preprocess_forum_list() (line 60 of
  /Users/seankennedy/Documents/_IWS/drupal/sites/all/themes/mothership/mothership/functions/forum.php).


I am mostly a front end guy so I have little experience with messing around in the database directly but not afraid to have a go if that's what it will take to fix it.
Option 1
Go to the Forum Topic manage fields and click edit in the forums field.
Check that the vocabulary is set to Forums
If it's not, delete the forum field and add the term reference field again.


Option 2
Have u posted content already to the forum? or do you care about the forum content? if not, disabling and uninstalling both Forum and Advanced Forum would be an option you could try and then enable them again.