When attempting to upgrade SDDC manager from 9.0.2.0100 to version 9.1.x receiving the error below.
"Upgrading SDDC Manager from source version 9.0.2.0100 to target version 9.1.0.0400 is not supported, as the source version's release date (2026-07-28) is after the target version's release date (2026-07-09), making it a newer release."
VMware Cloud Foundation 9.0.2.0100
This is a back-in-time version issue.
It is recommend to wait until the next compatible version of VCF is available before upgrading.
Please see Broadcom Product Interoperability Matrix > Upgrade Path > SDDC Manager for more details on the upgrade path for the component.