Search not working with 2 word queries

I’m trying to figure out what might be going amiss here. When I search a 2 word query it goes to a 404 page.

http://blog.lwolf.com

I’ve search a few different threads on this type of issue and haven’t been able to find a solution that seems to work. I’ve replaced the search.php and searchform.php templates and nothing seems to work. I’m using an old version of the roots template before they switched to bootstrap.

I’m wondering if any of this might be tied to my site being hosted on the IIS version of WordPress, or whether it’s just a simple template issue.