There is a known Cisco bug ID CSCvy96101 in which when trying to upload the 4.2(1d)B bundle you will get an error on the FSM saying "Remote Invocation Result: Sw Defect" with a description "Cannot execute image unpack (invalid Image)#" and the progress status will be stuck at 39%.
to address the issue you will need to remove the failed Download Task, and upgrade the Infrastructure code first to 4.2(1d) then upload your blade bundle.
Screenshot:
Happy Upgrading
