Got this error when importing a series of 5 SendPorts into a newly created BizTalk application:

Failed to update binding information. (mscorlib).
Additional Information:
Object reference not set to an instance of an object. (Microsoft.BizTalk.ExplorerOM).

My solution was that I needed to make a reference from the new application, to an existing application, which contained schemas, maps, etc.. used by these send ports. Basically, one of our developers needed a copy of the send ports to post data to the DEV database; so I exported my binding files, deleted everything except the 5 SQL SendPorts, then tried to import them into a new application to keep them separate.