we need more details.
Please attach the latest vmware.log of the VM to your next post and provide some background information.
See the vmware.log file in the considered VM's directory ( /vmfs/volumes/datastore/vm/...) after trying to start the VM and check the related events.
We need to have more details about your problem
Go to your proxy VM if you have one and release the VMDK files that correspond to the VM in question or Go to the VM directory and hit this command:- lsof | grep -i <VM-name>
Have a look if you have enough space in the datastore where the VM is stored. When you power on a VM it need free space to create the swap file. If your datastore is full it will not power on.