I created an HTTP Post adapter and packaged it all up in a setup package. When I installed it, I opened up the management console and started to configure the adapter and I received the the following error:

Failed to instantiate adapter “{Adapter Name}”.

Assembly file: “{dll source}”

Type name: “{Type}”

The problem was that the source was compiled with a dll that was on the development box, but not on the destination box. (In this case it was the Microsoft.Samples.BizTalk.Adapter.Common.dll) was not deployed to the GAC.

Once I put the assembly in the GAC, I didn’t have a problem.