We were seeing the same issue and it turned out that ePO was having difficulty talking to AD. Looking at our logs we were seeing LDAP bindings failing. We were doing LDAP/SSL and rolled back to just normal LDAP and it issue fixed itself, but further log investigation showed that it was possible that the LDAP port was typed in wrong. I would check all your registered AD servers and make sure the port being used is correct (not just that the 'test' button works....that was working for us too for whatever reason). The debug logs on the client will also have a error about being unable to contact your LDAP server but it's tough to find.
Below is the log I am getting prior to my push of MEEPC 6.0.1 agent.
2010-4-7 19:4:50,562 DEBUG EpoPlugin .\EpeEpoDataChannelEndpointServant.cpp: EPEEPO_data_channel_endpoint_servant::iDataReceived: 161: EEADMIN_1000_UsersAndMachineIDExc
2010-4-7 19:4:50,562 DEBUG MfeEpeHost From uuid = B115AA20-0396-4F41-A230-F61AE50E1DF7 From Service = To uuid = To Service = MfeEpeServiceDCServer Message = <element xsi:type="ns1:DCDataMsg"><sendTo serviceName="MfeEpeServiceDCServer" xsi:type="ns1:MfeEpeAddress"></sendTo><name>EEADMIN_1000_UsersAndMachineIDExc</ name><data>
<message>For input string: &quot;Administrator&quot;</message>
2010-4-7 19:4:50,578 ERROR EpoPlugin [0xEE000005] Failed to deserialize type
Refer the KB article : KB67529 & enable log to check further.
Sorry wrongly posted to u
Never mind. It seems there was an issue with my VMs. It worked well on physical machine.
Happy...!! But still don't understand - what the heck was that error for..."Failed to deserialize type"..
Make sure you are properly entering a domain\user when setting up the Registered Server as well. I saw a customer today who was receiving this error on the clients and upon further investigation they only had the user name setup for their Registered Server. Upon adding domain\user and waking the clients up, the activation started and errors went away.