PHP error in wp-includes/post-template.php

When I hit some pages on my local site (404 specifically) I am getting this error:

Trying to get property of non-object in /path-to-site/wp-includes/post-template.php line 264

doing a quick google search it appears there are a lot of live sites out there that probably do not even know they are getting this error as well.

here is what i searched:

“trying to get property of non-object in wp-includes/post-template.php line 264”

all results on page 1 were websites with that error on the page somewhere (most of the time hidden). Only 1 result is a stackoverflow that had no answers. I have a screenshot of my results, but I guess there is no way to upload it to here. BTW I do have debugging turned off.

Thanks for any help!