In case anyone has this issue in the future, there is a conflict with ImageMagick (MediaWiki’s native image resizer) and whatever Dreamhost uses by default for image resizing. Ironically, disabling ImageMagick will still allow you to resize images just fine. It’s worth noting that if you move off of Dreamhost for any reason, you’ll need to re-enable ImageMagick or another resizer or you’ll lose that functionality.
On line 82 of LocalSettings.php, simple make $wgUseImageMagick = false;
I hope this helps. I’m going to try to update the wiki as well as inform Dreammhost support whenever they answer my ticket.