When VCS is running, there are certain prerequisites to be met before the resource is disabled successfully.
An online non-persistent resource cannot be disabled. It must be in a clean OFFLINE state. (The state must be OFFLINE and IState must be NOT WAITING.)
If it is a persistent resource and the state is ONLINE on some of the systems, all dependent resources (parents) must be in clean OFFLINE state. (The state must be OFFLINE and IState must be NOT WAITING)
Therefore, before disabling the resource you may be required to take it offline (if it is non-persistent) and take other resources offline in the service group.