Teaser not being displayed when teaser and title option is selected

Issue Summary

I get the following error when I try to output the teaser for a node. I really need to be able to print thumbnail pictures along with the title of the node. But having a warm time in doing so. If there is another solution or a patch that I could use, it would be greatly appreciated. Been slugging about with this one for days now. Here is the output error:

Notice: Undefined property: stdClass::$teaser in template_preprocess_similarterms() (line 568 of /httpdocs/sites/all/modules/similarterms/similarterms.module).

I don't mind working around the teaser thing and finding someway to output the node title and a [thumbnail] picture that is in the node as well.