Using Get-Task in PowerCli can sometimes invalidly return this error:
Get-Task : date Get-Task The identifier x resulted in no objects.
Get-Task results in no objects this even if there is a valid ID. This is because the ID you have entered is case sensitive, because ESXi is based on Linux, which is case sensitive. Re-run Get-Task with capital letters in the correct places in the ID you are running the PowerCli command on.
If you are still getting The identifier x resulted in no objects, then try using a PowerCli command to get the identifier and piping that into a Get-Task command so the format is correct.