Http failure response for https://<vcf-operations-server>/vcf-operations/plug/sddc-108/plugin/api/v1/system/check-sets: 500 OK
VCF 9.0.0
Fleet Manager must be upgraded before the VCF Management components can be upgraded.
If you attempt to Upgrade Fleet manger from Lifecycle > Settings > Upgrade and it tells you that it is already on the latest version, this is a known issue: https://knowledge.broadcom.com/external/article/425279/attempts-to-upgrade-vcf-fleet-management.html