Trying to get property of non-object in theme_wikitools_create()

I get the below error message when trying to create a new wiki page that does not exist:

Notice: Trying to get property of non-object in theme_wikitools_create() (line 234 of /var/www/html/drupal/sites/all/modules/wikitools/wikitools.pages.inc).

I found this problem can be recreated like this:
1) create a new content type in Drupal
2) apply the wikitools to this new content type and hit save
3) delete content type from Drupal
4) create new wiki page and then you get the error.

I believe that when deleting the content type in Drupal, it is still being stored in the wikitools table and wikitools is trying to reference this non-existing content-type. The "fix" is to re-configure the wikitools in the modules menu and hit the SAVE button again. I believe by saving the wikitools configuration, it rewrites the table and removes that missing content type.