OpenDNS is a great tool for administrators. It allows you to block several types of unwanted traffic. However, sometimes it can block to much, or even block data inside of an application that doesn't show you the name of the domain it blocked. This is what happens in Microsoft Office's ClipArt search feature. In older versions of Office, ClipArt only included locally stored ClipArt galleries. In modern versions of Office, the ClipArt search actually reaches to the internet for ClipArt, and searches using bing.

If this happened to you, here are the domains you'll need to whitelist in OpenDNS to allow the ClipArt search to work again (after saving these in OpenDNS, it usually takes a few minutes to activate):

mm.bing.net

insertmedia.office.microsoft.com

If this works for you, make sure to leave a comment below to let everyone else know!