The 'makeStrictUpdateStrategy()' in document_source_merge.cpp is using 'updateWithStatus()' to do updates. The 'updateWithStatus()' is not implemented in 'MongoInterfaceShardServer'. So it ends up calling the method from its parent class 'MongoInterfaceStandalone'. We need to fix this by implementing 'updateWithStatus()' in 'MongoInterfaceShardServer'
We have also noticed that, when source is unsharded and target is sharded, mongos throws this error message instead of the original message of shard. We need to verify that it is not the case after the fix.