1. Identify VM with "Invalid" status.

2. Check if NFS datastore "Capacity" is "0 B".

3. Check on SynetoOS if the datastore appears mounted on local Hypervisor

4. Click on "change" deselect "host" confirm "Update" to unmount datastore , now re-mount the datastore on host by clicking on "change" select "host" and "Update"