I am getting similar error after upgrading to LDDA 9.6:
Exception in While loop Object reference not set to an instance of an object. at ManagedPlanet.RapidDeploy.RDService.WatchClients()
LDMS 9.5 SP2:
[HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\LANDesk\ManagementSuite\Setup\Version\Patches]
"LANDesk Software 9.50 - Service Pack 2"="9.50.2.85"
"LANDesk Software 9.50.3 - Software License Monitoring"="9.50.3"
"LANDesk SmartVue for Management Suite 9.5"="9.50.2"
"LANDesk Software 9.50.1 - BASE"="2014-0417"
"LANDesk Software 9.50.1 - RC"="2014-0417"
"CROpensslNonFips - libeay32.dll"="1.0.1g"
"CROpensslNonFips - Terminate.exe"="9.50.2.4"
"LANDESK Software - Data Analytics"="9.60.0383"
@=""
"LANDESK Software - Data Analytics Content"="9.60.0424"
LDDA 9.6