Experienced a rather interesting problem with the MQSC adapter in a multiple server BizTalk Group. It seems only the first server gets the COM+ application installed.
The other servers, 2 in this case didn't have it. The errors you'll see:
The adapter failed to transmit message going to send port "SENDPORTNAME" with URL "mqsc://SOMECHANNEL.SVRCONN/tcp/mqserver.com(50001)/QMANAGER/QUEUENAME". It will be retransmitted after the retry interval specified for this Send Port. Details:"Class not registered (Exception from HRESULT: 0x80040154 (REGDB_E_CLASSNOTREG))".
The BYOT Gateway could not delegate the activation. The component being created may be incorrectly configured. Process Name: BTSNTSvc64.exe
Error Code = 0x80040154 : Class not registered
COM+ Services Internals Information:
File: d:\w7rtm\com\complus\src\comsvcs\byot\byotex.cpp, Line: 450
Comsvcs.dll file version: ENU 2001.12.8530.16385 shp
The solution is to either remove the MQSC adapter from BizTalk and repair HIS or you can export the MQSC COM+ application from a server that has it and import it.
The first server I tried to export the application from kept exporting the MQS application despite click on MQSC (tried multiple times). In the end I found another server that had it and was able to import successfully. Not sure what that was about but I'm moving on.