VCF day N operation buttons or links may look grayed out after multiple parallel add host or add cluster operations.
Vmware Cloud Foundation 4.5.1
Hierarchical locking was introduced in 4.5. If you run parallel add host operations to different clusters or parallel add cluster operations to different workload domains, the system may not release system locks after the operations complete. These locks prevent certain operations until the locks are released.
This is resolved in VMware Cloud Foundation 4.5.2