question

Have you created the Park locations in your groups?

Then add the "users of this park location".  Lastly, add a presence key for each park Zone you added in groups on the phones of the users added.

Also, 

• Does this happen on all deskphones at the location? or just 1 or 2? 
• Is your router configured to have RC ports open? Often times, failed transfer/parked calls can be due to the router not being configured correctly. 

Yes to all your questions.

Added to Groups

Added all users to all 3 groups I created.

Added to presence of each phone.

Does it happen on all phones?   it worked when i first setup, then did not work at all.

Configured Firewall router with following:
5060-6000 UDP and TCP (These ports allow the phones to register)
8000-8200 UDP only (These ports are used by the Softphones for message synchronization)
16384-65535 UDP only (These ports carry voice traffic - the RTP streams) 
8801-8802 UDP and TCP (These ports are for RC Meetings signaling)
Port  80 and 443 TCP only (These ports are used for initial phone provisioning)
Port  123 UDP only (This port allows NTP: date and time updates)
4000-5000 UDP (Mobile App Media)
20000-60000 UDP (RTP and SRTP Soft phone) 

Does it happen on all phones?   it worked when i first setup, then did not work at all."

It didn't work for all phones or just some?
What extension have this problem? I'm going to check the phone on the back end. 

I got it working.  

First, I failed to explain that we have 3 numbers that are not associated to phones, but that ring to different sets of phones.  

Each of these numbers is using a different extension that does not have a phone attached to it.  For example, when a call comes in on NumberA, that number is set as the autoreceptionist that goes to ext 123(just example).  When this happens, we have advanced rules that forward calls to ring simultaneously on ext 101, 102, 103, 104, 105(examples) when NumberA(ext 123) is dialed.  

I added all users(ext 101-105) to the park group except the extension(ext 123) that first receive the calls.

To resolve the issue, I had to add the user for NumberA(ext 123) as well to the group.  Then I had to also add the presence on NumberA(ext 123) to be able to park the calls.

Now I cant intercom, but that is another problem entirely.

Thank you for all of your quick responses.

Glad you got that sorted.  Please make a new post about your intercom issue.  I am curious, if it is that you can't intercom after parking a call?  I have a customer with that issue that I have not been able to resolve and they use the same call flow you described.