pcns on vMa 5.1

Hi,
I have a problem with APC PCNS on VMA 5.1.
I installed version 3.0.1 and unfortunately not work, in addition to the attempt to power off the console hangs https://vma:6547, the connection is lost. Just restart VMA helps.
Can I use an older version of VMA 5.0 to 5.1 to vSphere virtual machines off?
Are there other ways to safely close the virtual machine after a power failure?
Using immediately thank you