I ran into a similar issue yesterday with the my VDP appliance being stuck in state Admin. After cobbling together little snippets from different disparate areas of the interwebs, I was able to get my system running again.
The key is opening an SSH session to your appliance and using the dpnctl command. This set of steps worked for me:
1) Open an SSH session to VDP using putty or similar, login as root.
2) Type 'dpnctl status'. This will show you a list of VDP services that are or aren't running. In my case it told me that my gsan was running in a state of 'degraded'.
3) If a service is started but degraded, use dpnctl to stop the service. If it needs to stop, type 'dpnctl stop gsan' (or 'dpnctl stop MCS' or whatever, you can also do 'dpnctl stop all').
4) Now start the service(s) in question with 'dpnctl start gsan' (or 'dpnctl start all').
That's all I needed. Hope this helps!
P.S. Since VMware's VDP appears to be a rebrand of a former EMC product called AVAMAR, a lot of the info about VDP command line can be found if you search for AVAMAR commands. Note to VMware: if would be super helpful if you'd put more VDP documentation online, especially related to the command line. It looks like a lot of people are frustrated not because it's a bad product, but because you don't have enough documentation available to empower us to fix this stuff ourselves. Just my $0.02.