ESXi Upgrade Pre-Check Fails with Error “Failed to Deserialize Software Specification” in SDDC Manager

Products

• VMware SDDC Manager

Issue/Introduction

• When performing an ESXi upgrade using SDDC Manager, the pre-check fail with the error: 'Failed to deserialize software specification'.
• This below error appears in the SDDC Manager UI during the upgrade preparation or image validation phase.
  

Environment

VMware Cloud Foundation 5.2.x

Cause

This occurs due to restricted or failed network connectivity to Broadcom’s content delivery servers (dl.broadcom.com) during the image download process.

As a result, the deserialization of the incomplete software specification failed, preventing the upgrade from proceeding.

Resolution

Action Plan:

1. Verify network access from SDDC Manager and vCenter to the external repositories, particularly:

   dl.broadcom.com

2. Ensure uninterrupted connectivity during image import and upgrade operations.

3. Delete any existing (stale) personalities through the API Explorer.

   • Reference Link:  Remove a wrong/unwanted image present in image management tab of SDDC.

4. Recreate the image personality in SDDC Manager after confirming successful network access.

5. Retry the ESXi upgrade process once the image and its software specification are fully downloaded and validated.

Restoring network connectivity and recreating the image personality ensures the JSON file downloads correctly and the cluster upgrade completes successfully.