Error Object Reference Not Set to an Instance of an Object when Adding an Agent to Protection (4036251)

The error message “Object reference not set to an instance of an object,” sometimes displayed as “System.NullReferenceException: Object reference not set to an instance of an object,” is an indication that the software application cannot find information it is seeking.

If you are attempting to add (or re-add) an agent to protection in the Core Console and you see an error very similar to the one below, then the issue is an empty registry key holding onto a reference the system needs to properly protect an agent. This is possibly a result of the Windows registry not cleaning up properly when a machine was previously removed from protection.

NOTE: One solution in this article includes making changes to the Windows registry. Quest recommends backing up the Windows registry before making any changes. For information on backing up the registry, see “How to Back Up the Windows Registry” - http://www.appassure.com/support/KB/how-to-backup-the-registry/ .

Error message:

Call to service method https://localhost:8006/apprecovery/api/core/agents/new POST failed: Object reference not set to an instance of an object.
System.NullReferenceException: Object reference not set to an instance of an object.
at Replay.ServiceHost.Implementation.Configuration.RegistryConfigurationSer vice.ReadDataFromRegistry[T](String name, T& value)
at Replay.ServiceHost.Implementation.Configuration.RegistryConfigurationReader.ReadSetting[T](String name)
at Replay.ServiceHost.Implementation.Configuration.ConfigurationExtensions.ReadSingleSetting[T](IConfigurationService configurationService, String name)
at Replay.Core.Implementation.Agents.AgentsService.CheckAgentPairingInternal(AgentDescriptor agentDescriptor)
at Replay.Core.Implementation.Agents.AgentsService.AddAgent(AgentDescriptor agentDescriptor, AgentProtectionConfiguration protectionConfig)
at Replay.Core.Management.Agents.AgentsManagement.AddAgent(AddAgentRequest addAgentRequest)

Complete the following steps.

Solution 1

1. On the AppAssure 5 Core, stop the Core service.
2. From a command prompt, open Microsoft Windows Registry Editor (REGEDIT).
3. Navigate to  HKEY_LOCAL_MACHINE\SOFTWARE\AppRecovery\Core\Agents. Each protected agent has a registry key (a long string of numbers and letters).  You should see one key for each protected agent.
4. Click on each entry under Agents, and look for the HostUri entry with the name matching the agent machine you are trying to protect which is giving you an error.
5. Under agents, when you find that key, delete it, save and exit REGEDIT.
6. On the AppAssure Core, start the Core service.

Solution 2

Upgrade to 5.3.5.64611 or higher.