I had the same problem with a T630, upgrading from 220.127.116.11 to 18.104.22.168 and resolved the issue by following the Installation instructions in the Release Notes that say:
• From the management station, remotely update the firmware using the iDRAC web interface: 1. Extract the firmware image self-extracting file to the management station. 2. Open the iDRAC web interface using a supported web browser. 3. Log in as administrator. 4. Go to Overview -> iDRAC Settings -> Update and Rollback -> Update. The Firmware Update page is displayed. 5. Click Browse, select the .d7 firmware image file that you extracted (step 1), or the Dell Update Package (DUP) for Windows, and click Upload. 6. Wait for the upload to complete. After the upload is completed, the Update Details section displays the firmware file uploaded to iDRAC and the status. 7. Select the firmware file and click Install or Install and Reboot. If it is a DUP, Install dynamically changes to Install and Reboot and at the same time the Install Next Reboot is activated. When you click Install and Reboot or Install Next Reboot, the message “Updating Job Queue” is displayed. 8. Click OK. The Job Queue page is displayed, where you can view and manage the firmware update. After the update is completed, iDRAC restarts automatically.
You can extract the firmware.d7 image by opening the EXE file with a ZIP extraction utility (e.g. WinZip).