When importing bindings into an application, you might get this error:
Failed to update binding information (mscorlib):
Additional Information
BizTalk Import Bindings Error: Object reference not set to an instance of an object. (Microsoft.BizTalk.ExplorerOM)

While there maybe multiple reasons for this error, here’s the one I found.

The map I was referencing in a Receive Port existed, but it was in a different solution. (I had a typo in the application name when I deployed it). I either move the map from one application to another, or delete it and re-deploy it with the correctly spelled name. Then it worked fine.