VMware Cloud Director 10.6
This is an issue in the UI at coding level, where the option is not executed correctly.
This is a known issue in VMware Cloud Director 10.6 and it will be fixed on a later Cloud Director release.
Deletion of Snapshots can be triggered from multiple dialogs, and currently working only by executing the steps as per Remove a Snapshot of a vApp in the VMware Cloud Director Tenant Portal or see section Delete a Snapshot of a Virtual Machine in the VMware Cloud Director Tenant Portal